more refactoring (not limited to attribute handling)

* completed separation of attributes and standard (column) values
* improved tests a lot

That work is still not finished, so expect things to fail horribly.

git-svn-id: http://svn.openslx.org/svn/openslx/trunk@1443 95ad53e4-c205-0410-b2fa-d234c58c8868

16 files changed, 1753 insertions, 878 deletions

diff --git a/config-db/OpenSLX/ConfigDB.pm b/config-db/OpenSLX/ConfigDB.pm
index 95183c95..289f6f7f 100644
--- a/config-db/OpenSLX/ConfigDB.pm
+++ b/config-db/OpenSLX/ConfigDB.pm
@@ -561,6 +561,15 @@ sub fetchSystemByFilter
 		$filter, $resultCols, $attrFilter
 	);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each system, too:
+	if (!defined $resultCols) {
+		foreach my $system (@systems) {
+			$system->{attrs} 
+				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
+		}
+	}
+
 	return wantarray() ? @systems : shift @systems;
 }
 
@@ -596,91 +605,16 @@ sub fetchSystemByID
 	
 	# unless specific result cols have been given, we mix in the attributes
 	# of each system, too:
-#	if (!defined $resultCols) {
-#		foreach my $system (@systems) {
-#			$system->{attrs} 
-#				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
-#		}
-#	}
+	if (!defined $resultCols) {
+		foreach my $system (@systems) {
+			$system->{attrs} 
+				= $self->{'meta-db'}->fetchSystemAttrs($system->{id});
+		}
+	}
 
 	return wantarray() ? @systems : shift @systems;
 }
 
-=item C<fetchSystemAttrs($systemID, [$attrNames])>
-
-Fetches and returns the information about the attributes of the system
-with the given ID.
-
-=over
-
-=item Param C<$systemID>
-
-The ID of the system whose attributes you are interested in.
-
-=item Param C<$attrNames> [Optional]
-
-A comma-separated list of attribute names that shall be returned. If not 
-defined,all available attributes will be returned.
-
-=item Return Value
-
-An array of hash-refs containing the resulting data rows (or a single hash-ref
-mapping all attribute names to the respective value).
-
-=back
-
-=cut
-
-sub fetchSystemAttrs
-{
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrNames = shift;
-
-	my @attrs = $self->{'meta-db'}->fetchSystemAttrs($systemID, $attrNames);
-
-	return wantarray() ? @attrs : shift @attrs;
-}
-
-=item C<fetchSystemAttrsAsHash($systemID, [$attrNames])>
-
-Fetches and returns the information about the attributes of the system
-with the given ID.
-
-=over
-
-=item Param C<$systemID>
-
-The ID of the system whose attributes you are interested in.
-
-=item Param C<$attrNames> [Optional]
-
-A comma-separated list of attribute names that shall be returned. If not 
-defined,all available attributes will be returned.
-
-=item Return Value
-
-A single hash-ref mapping all attribute names to their respective value.
-
-=back
-
-=cut
-
-sub fetchSystemAttrsAsHash
-{
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrNames = shift;
-
-	my @attrs = $self->{'meta-db'}->fetchSystemAttrs($systemID, $attrNames);
-
-	my $Result = {};
-	foreach my $attr (@attrs) {
-		$Result->{$attr->{name}} = $attr->{value};
-	}
-	return $Result;
-}
-
 =item C<fetchSystemIDsOfExport($id)>
 
 Fetches the IDs of all systems that make use of the export with the given ID.
@@ -787,10 +721,23 @@ An array of hash-refs containing the resulting data rows.
 
 sub fetchClientByFilter
 {
-	my $self   = shift;
-	my $filter = shift;
+	my $self       = shift;
+	my $filter     = shift;
+	my $resultCols = shift;
+	my $attrFilter = shift;
 
-	my @clients = $self->{'meta-db'}->fetchClientByFilter($filter);
+	my @clients = $self->{'meta-db'}->fetchClientByFilter(
+		$filter, $resultCols, $attrFilter
+	);
+
+	# unless specific result cols have been given, we mix in the attributes
+	# of each client, too:
+	if (!defined $resultCols) {
+		foreach my $client (@clients) {
+			$client->{attrs} 
+				= $self->{'meta-db'}->fetchClientAttrs($client->{id});
+		}
+	}
 
 	return wantarray() ? @clients : shift @clients;
 }
@@ -825,6 +772,15 @@ sub fetchClientByID
 
 	my @clients = $self->{'meta-db'}->fetchClientByID($ids, $resultCols);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each client, too:
+	if (!defined $resultCols) {
+		foreach my $client (@clients) {
+			$client->{attrs} 
+				= $self->{'meta-db'}->fetchClientAttrs($client->{id});
+		}
+	}
+
 	return wantarray() ? @clients : shift @clients;
 }
 
@@ -911,8 +867,20 @@ sub fetchGroupByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
-	my @groups = $self->{'meta-db'}->fetchGroupByFilter($filter, $resultCols);
+	my @groups = $self->{'meta-db'}->fetchGroupByFilter(
+		$filter, $resultCols, $attrFilter
+	);
+
+	# unless specific result cols have been given, we mix in the attributes
+	# of each group, too:
+	if (!defined $resultCols) {
+		foreach my $group (@groups) {
+			$group->{attrs} 
+				= $self->{'meta-db'}->fetchGroupAttrs($group->{id});
+		}
+	}
 
 	return wantarray() ? @groups : shift @groups;
 }
@@ -947,6 +915,15 @@ sub fetchGroupByID
 
 	my @groups = $self->{'meta-db'}->fetchGroupByID($ids, $resultCols);
 
+	# unless specific result cols have been given, we mix in the attributes
+	# of each group, too:
+	if (!defined $resultCols) {
+		foreach my $group (@groups) {
+			$group->{attrs} 
+				= $self->{'meta-db'}->fetchGroupAttrs($group->{id});
+		}
+	}
+
 	return wantarray() ? @groups : shift @groups;
 }
 
@@ -1707,6 +1684,43 @@ sub changeClient
 	return $self->{'meta-db'}->changeClient($clientIDs, $valRows);
 }
 
+=item C<setClientAttr($clientID, $attrName, $attrValue)>
+
+Sets a value for an attribute of the given client. If the client already
+has a value for this attribute, it will be overwritten.
+
+=over
+
+=item Param C<clientID>
+
+The ID of the client whose attribute shall be changed.
+
+=item Param C<attrName>
+
+The name of the attribute to change.
+
+=item Param C<attrValue>
+
+The new value for the attribute.
+
+=item Return Value
+
+C<1> if the attribute could be set, C<undef> if not.
+
+=back
+
+=cut
+
+sub setClientAttr
+{
+	my $self      = shift;
+	my $clientID  = shift;
+	my $attrName  = shift;
+	my $attrValue = shift;
+
+	return $self->{'meta-db'}->setClientAttr($clientID, $attrName, $attrValue);
+}
+
 =item C<setSystemIDsOfClient($clientID, @$systemIDs)>
 
 Specifies all systems that should be offered for booting by the given client.
@@ -1987,6 +2001,43 @@ sub removeGroup
 	return $self->{'meta-db'}->removeGroup($groupIDs);
 }
 
+=item C<setGroupAttr($groupID, $attrName, $attrValue)>
+
+Sets a value for an attribute of the given group. If the group already
+has a value for this attribute, it will be overwritten.
+
+=over
+
+=item Param C<groupID>
+
+The ID of the group whose attribute shall be changed.
+
+=item Param C<attrName>
+
+The name of the attribute to change.
+
+=item Param C<attrValue>
+
+The new value for the attribute.
+
+=item Return Value
+
+C<1> if the attribute could be set, C<undef> if not.
+
+=back
+
+=cut
+
+sub setGroupAttr
+{
+	my $self      = shift;
+	my $groupID  = shift;
+	my $attrName  = shift;
+	my $attrValue = shift;
+
+	return $self->{'meta-db'}->setGroupAttr($groupID, $attrName, $attrValue);
+}
+
 =item C<changeGroup(@$groupIDs, @$valRows)>
 
 Changes the data of one or more groups.
@@ -2588,13 +2639,17 @@ sub mergeAttributes
 	my $target = shift;
 	my $source = shift;
 
-	foreach my $key (keys %$source) {
-		next if !isAttribute($key);
-		my $sourceVal = $source->{$key} || '';
-		my $targetVal = $target->{$key} || '';
-		if (length($sourceVal) && !length($targetVal)) {
-			vlog(3, _tr("merging %s (val=%s)", $key, $sourceVal));
-			$target->{$key} = $sourceVal;
+	my $sourceAttrs = $source->{attrs} || {};
+
+	$target->{attrs} ||= {};
+	my $targetAttrs = $target->{attrs};
+
+	foreach my $key (keys %$sourceAttrs) {
+		my $sourceVal = $sourceAttrs->{$key};
+		my $targetVal = $targetAttrs->{$key};
+		if (defined $sourceVal && !defined $targetVal) {
+			vlog(0, _tr("merging %s (val=%s)", $key, $sourceVal));
+			$targetAttrs->{$key} = $sourceVal;
 		}
 	}
 
@@ -2628,11 +2683,16 @@ sub pushAttributes
 	my $target = shift;
 	my $source = shift;
 
-	foreach my $key (grep { isAttribute($_) } keys %$source) {
-		my $sourceVal = $source->{$key} || '';
-		if (length($sourceVal)) {
+	my $sourceAttrs = $source->{attrs} || {};
+
+	$target->{attrs} ||= {};
+	my $targetAttrs = $target->{attrs};
+
+	foreach my $key (keys %$sourceAttrs) {
+		my $sourceVal = $sourceAttrs->{$key};
+		if (defined $sourceVal) {
 			vlog(3, _tr("pushing %s (val=%s)", $key, $sourceVal));
-			$target->{$key} = $sourceVal;
+			$targetAttrs->{$key} = $sourceVal;
 		}
 	}
 
@@ -2826,54 +2886,7 @@ sub _checkAndUpgradeDBSchemaIfNecessary
 				$DbSchema->{version}, $currVersion
 			)
 		);
-		foreach my $v (sort { $a <=> $b } keys %DbSchemaHistory) {
-			next if $v <= $currVersion;
-			my $changeSet = $DbSchemaHistory{$v};
-			foreach my $c (0 .. scalar(@$changeSet) - 1) {
-				my $changeDescr = @{$changeSet}[$c];
-				my $cmd         = $changeDescr->{cmd};
-				if ($cmd eq 'add-table') {
-					$metaDB->schemaAddTable(
-						$changeDescr->{'table'},
-						$changeDescr->{'cols'},
-						$changeDescr->{'vals'}
-					);
-				} elsif ($cmd eq 'drop-table') {
-					$metaDB->schemaDropTable($changeDescr->{'table'});
-				} elsif ($cmd eq 'rename-table') {
-					$metaDB->schemaRenameTable(
-						$changeDescr->{'old-table'},
-						$changeDescr->{'new-table'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'add-columns') {
-					$metaDB->schemaAddColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'new-cols'},
-						$changeDescr->{'new-default-vals'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'drop-columns') {
-					$metaDB->schemaDropColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'drop-cols'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'rename-columns') {
-					$metaDB->schemaRenameColumns(
-						$changeDescr->{'table'},
-						$changeDescr->{'col-renames'},
-						$changeDescr->{'cols'}
-					);
-				} elsif ($cmd eq 'perl-func') {
-					if (!$changeDescr->{code}->($self)) {
-						croak _tr('problem in perl-func cmd!');
-					}
-				} else {
-					croak _tr('UnknownDbSchemaCommand', $cmd);
-				}
-			}
-		}
+		$metaDB->schemaUpgradeDBFrom($currVersion);
 		$metaDB->schemaSetDBVersion($DbSchema->{version});
 		vlog(1, _tr('upgrade done'));
 	} else {
diff --git a/config-db/OpenSLX/DBSchema.pm b/config-db/OpenSLX/DBSchema.pm
index 54596c9f..801f50a9 100644
--- a/config-db/OpenSLX/DBSchema.pm
+++ b/config-db/OpenSLX/DBSchema.pm
@@ -33,12 +33,7 @@ use OpenSLX::Basics;
 
 use POSIX qw(locale_h);
 my $lang = setlocale(LC_MESSAGES);
-my $country;
-if ($lang =~ m[^\w\w_(\w\w)]) {
-	$country = lc($1);
-} else {
-	$country = 'us';
-}
+my $country = $lang =~ m[^\w\w_(\w\w)] ? lc($1) : 'us';
 
 ################################################################################
 ### DB-schema definition
@@ -73,12 +68,22 @@ $DbSchema = {
 			],
 			'vals' => [
 				{	# add default client
-					'id' => 0,
-					'name' => '<<<default>>>',
-					'comment' => 'internal client that holds default values',
+					'id'         => 0,
+					'name'       => '<<<default>>>',
+					'comment'    => 'internal client that holds default values',
+					'unbootable' => 0,
 				},
 			],
 		},
+		'client_attr' => {
+			# attributes of clients
+			'cols' => [
+				'id:pk',			# primary key
+				'client_id:fk',		# foreign key to client
+				'name:s.128',		# attribute name
+				'value:s.255',		# attribute value
+			],
+		},
 		'client_system_ref' => {
 			# clients referring to the systems they should offer for booting
 			'cols' => [
@@ -134,6 +139,15 @@ $DbSchema = {
 				'comment:s.1024',	# internal comment (optional, for admins)
 			],
 		},
+		'group_attr' => {
+			# attributes of groups
+			'cols' => [
+				'id:pk',			# primary key
+				'group_id:fk',		# foreign key to group
+				'name:s.128',		# attribute name
+				'value:s.255',		# attribute value
+			],
+		},
 		'group_client_ref' => {
 			# groups referring to their clients
 			'cols' => [
@@ -394,146 +408,9 @@ $DbSchema = {
 };
 
 ################################################################################
-### DB-schema history
-###
-### 	This hash contains a description of all the different changes that have
-### 	taken place on the schema. Each version contains a changeset (array)
-### 	with the commands that take the schema from the last version to the
-### 	current.
-###
-### 	The following 'cmd'-types are supported:
-###
-### 		add-table => creates a new table
-### 			'table' => contains the name of the new table
-### 			'cols'	=> contains a list of column descriptions
-### 			'vals'	=> optional, contains list of data hashes to be inserted
-### 					   into new table
-###
-### 		drop-table => drops an existing table
-### 			'table	=> contains the name of the table to be dropped
-###
-### 		rename-table => renames a table
-### 			'old-table' => contains the old name of the table
-### 			'new-table' => contains the new name of the table
-### 			'cols' => contains a full list of column descriptions
-###
-### 		add-columns => adds columns to a table
-### 			'table' => the name of the table the columns should be added to
-### 			'new-cols' => contains a list of new column descriptions
-### 			'new-default-vals' => optional, a list of data hashes to be used
-###							 		  as default values for the new columns
-### 			'cols' => contains a full list of resulting column descriptions
-###
-### 		drop-columns => drops columns from a table
-### 			'table' => the name of the table the columns should be dropped from
-### 			'drop-cols' => a list of column names to be dropped
-### 			'cols'	=> contains a full list of resulting column descriptions
-###
-###			perl-func => a perl function invoked with config-DB object as param
-### 			'code'	=> the function (sub) that shall be executed
-###
-################################################################################
-
-%DbSchemaHistory = (
-	'0.01' => [
-		# there's no need to upgrade to the initial schema version, as we
-		# create the newest schema automatically if none exists yet.
-	],
-	'0.2' => [
-		# move attributes into separate tables ...
-		#
-		# ... system attributes ...
-		{
-			'cmd' => 'add-table',
-			'table' => 'system_attr',
-			'cols' => [
-				'id:pk',
-				'system_id:fk',
-				'name:s.128',
-				'value:s.255',
-			],
-		},
-		{
-			'cmd' => 'perl-func',
-			'code' => sub {
-				my $configDB = shift;
-				foreach my $system ($configDB->fetchSystemByFilter()) {
-					foreach my $key (keys %$system) {
-						next if substr($key, 0, 5) ne 'attr_';
-						my $attrValue = $system->{$key} || '';
-						next if $system->{id}>0 && !length($attrValue);
-						my $newAttrName = substr($key, 5);
-						$configDB->setSystemAttr(
-							$system->{id}, $newAttrName, $attrValue
-						);
-					}
-				}
-				1;
-			}
-		},
-		{
-			'cmd' => 'drop-columns',
-			'table' => 'system',
-			'drop-cols' => [
-				'attr_automnt_dir',
-				'attr_automnt_src',
-				'attr_country',
-				'attr_dm_allow_shutdown',
-				'attr_hw_graphic',
-				'attr_hw_monitor',
-				'attr_hw_mouse',
-				'attr_late_dm',
-				'attr_netbios_workgroup',
-				'attr_nis_domain',
-				'attr_nis_servers',
-				'attr_ramfs_fsmods',
-				'attr_ramfs_miscmods',
-				'attr_ramfs_nicmods',
-				'attr_ramfs_screen',
-				'attr_sane_scanner',
-				'attr_scratch',
-				'attr_slxgrp',
-				'attr_start_alsasound',
-				'attr_start_atd',
-				'attr_start_cron',
-				'attr_start_dreshal',
-				'attr_start_ntp',
-				'attr_start_nfsv4',
-				'attr_start_printer',
-				'attr_start_samba',
-				'attr_start_snmp',
-				'attr_start_sshd',
-				'attr_start_syslog',
-				'attr_start_x',
-				'attr_start_xdmcp',
-				'attr_tex_enable',
-				'attr_timezone',
-				'attr_tvout',
-				'attr_vmware',
-			],
-			'cols' => [
-				'id:pk',
-				'export_id:fk',
-				'name:s.64',
-				'label:s.64',
-				'kernel:s.128',
-				'kernel_params:s.512',
-				'hidden:b',
-				'comment:s.1024',
-			],
-		},
-		#
-		# ... client attributes ...
-		#
-		# ... group attributes ...
-	],
-);
-
-
-################################################################################
 ###
-### Load all available AttrInfo modules and build the complete hash containing
-### info about all known attributes from that.
+### Load the available AttrInfo-modules and build a hash containing info about
+### all known attributes from the data contained in those modules.
 ###
 ################################################################################
 
diff --git a/config-db/OpenSLX/MetaDB/DBI.pm b/config-db/OpenSLX/MetaDB/DBI.pm
index 774ab90e..98754777 100644
--- a/config-db/OpenSLX/MetaDB/DBI.pm
+++ b/config-db/OpenSLX/MetaDB/DBI.pm
@@ -78,14 +78,13 @@ sub _trim
 
 sub _buildFilterClause
 {
-	my $self      = shift;
-	my $filter    = shift || {};
-	my $connector = shift;
+	my $self         = shift;
+	my $filter       = shift || {};
+	my $filterClause = shift || '';
 
-	my $filterClause = '';
-	my ($quotedVal);
+	my ($connector, $quotedVal);
 	foreach my $col (keys %$filter) {
-		$connector = !defined $connector ? 'WHERE' : 'AND';
+		$connector = !length($filterClause) ? 'WHERE' : 'AND';
 		if (defined $filter->{$col}) {
 			$quotedVal = $self->{dbh}->quote($filter->{$col});
 			$filterClause .= " $connector $col = $quotedVal";
@@ -94,42 +93,48 @@ sub _buildFilterClause
 		}
 	}
 	
-	return $filterClause;
+	return $filterClause || '';
 }
 
 sub _buildAttrFilterClause
 {
-	my $self       = shift;
-	my $attrFilter = shift || {};
-	my $connector = shift;
+	my $self         = shift;
+	my $attrFilter   = shift || {};
+	my $table        = shift;
+	my $filterClause = shift || '';
+
+	my %tableMap = (
+		'client' => 'client',
+		'group'  => 'groups',
+		'system' => 'system',
+	);
 
-	my $attrFilterClause = '';
-	my ($quotedName, $quotedValue);
+	my ($connector, $quotedName, $quotedValue);
 	foreach my $name (keys %$attrFilter) {
-		$connector = !defined $connector ? 'WHERE' : 'AND';
+		$connector = !length($filterClause) ? 'WHERE' : 'AND';
 		$quotedName = $self->{dbh}->quote($name);
 		if (defined $attrFilter->{$name}) {
 			$quotedValue = $self->{dbh}->quote($attrFilter->{$name});
-			$attrFilterClause .= <<"			End-of-Here";
+			$filterClause .= <<"			End-of-Here";
 				$connector EXISTS (
-					SELECT name FROM system_attr
+					SELECT name FROM ${table}_attr
 					WHERE name = $quotedName 
 					AND value = $quotedValue
-					AND system_id = system.id
+					AND ${table}_id = $tableMap{$table}.id
 				)
 			End-of-Here
 		} else {
-			$attrFilterClause .= <<"			End-of-Here";
+			$filterClause .= <<"			End-of-Here";
 				$connector NOT EXISTS (
-					SELECT name FROM system_attr
+					SELECT name FROM ${table}_attr
 					WHERE name = $quotedName 
-					AND system_id = system.id
+					AND ${table}_id = $tableMap{$table}.id
 				)
 			End-of-Here
 		}
 	}
 
-	return $attrFilterClause;
+	return $filterClause;
 }
 
 sub _doSelect
@@ -245,13 +250,13 @@ sub fetchSystemByFilter
 	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
-	my $filterClause = $self->_buildFilterClause($filter, 'AND');
-	my $attrFilterClause = $self->_buildAttrFilterClause($attrFilter, 'AND');
+	my $filterClause = $self->_buildFilterClause($filter);
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'system', $filterClause
+	);
 	my $sql = <<"	End-of-Here";
 		SELECT $resultCols FROM system
-		WHERE 1=1
 		$filterClause
-		$attrFilterClause
 	End-of-Here
 	return $self->_doSelect($sql);
 }
@@ -273,17 +278,17 @@ sub fetchSystemAttrs
 {
 	my $self      = shift;
 	my $systemID  = $self->{dbh}->quote(shift);
-	my $attrNames = shift;
 
 	my $sql = <<"	End-of-Here";
-		SELECT id, name, value FROM system_attr
+		SELECT name, value FROM system_attr
 		WHERE system_id = $systemID
 	End-of-Here
-	if (defined $attrNames) {
-		my $attrList = join ',', map { $self->{dbh}->quote($_) } @$attrNames;
-		$sql .= " AND name IN ($attrList)";
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
 	}
-	return $self->_doSelect($sql);
+	return $Result;
 }
 
 sub fetchSystemIDsOfExport
@@ -324,10 +329,17 @@ sub fetchClientByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
 	my $filterClause = $self->_buildFilterClause($filter);
-	my $sql = "SELECT $resultCols FROM client $filterClause";
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'client', $filterClause
+	);
+	my $sql = <<"	End-of-Here";
+		SELECT $resultCols FROM client
+		$filterClause
+	End-of-Here
 	return $self->_doSelect($sql);
 }
 
@@ -344,6 +356,23 @@ sub fetchClientByID
 	return $self->_doSelect($sql);
 }
 
+sub fetchClientAttrs
+{
+	my $self     = shift;
+	my $clientID = $self->{dbh}->quote(shift);
+
+	my $sql = <<"	End-of-Here";
+		SELECT name, value FROM client_attr
+		WHERE client_id = $clientID
+	End-of-Here
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
+	}
+	return $Result;
+}
+
 sub fetchClientIDsOfSystem
 {
 	my $self     = shift;
@@ -371,10 +400,17 @@ sub fetchGroupByFilter
 	my $self       = shift;
 	my $filter     = shift;
 	my $resultCols = shift;
+	my $attrFilter = shift;
 
 	$resultCols = '*' unless (defined $resultCols);
 	my $filterClause = $self->_buildFilterClause($filter);
-	my $sql = "SELECT $resultCols FROM groups $filterClause";
+	$filterClause = $self->_buildAttrFilterClause(
+		$attrFilter, 'group', $filterClause
+	);
+	my $sql = <<"	End-of-Here";
+		SELECT $resultCols FROM groups
+		$filterClause
+	End-of-Here
 	return $self->_doSelect($sql);
 }
 
@@ -391,6 +427,23 @@ sub fetchGroupByID
 	return $self->_doSelect($sql);
 }
 
+sub fetchGroupAttrs
+{
+	my $self    = shift;
+	my $groupID = $self->{dbh}->quote(shift);
+
+	my $sql = <<"	End-of-Here";
+		SELECT name, value FROM group_attr
+		WHERE group_id = $groupID
+	End-of-Here
+	my @attrs = $self->_doSelect($sql);
+	my $Result = {};
+	foreach my $attr (@attrs) {
+		$Result->{$attr->{name}} = $attr->{value};
+	}
+	return $Result;
+}
+
 sub fetchGroupIDsOfSystem
 {
 	my $self     = shift;
@@ -505,20 +558,22 @@ sub _doUpdate
 
 	my $dbh    = $self->{'dbh'};
 	my $valRow = (@$valRows)[0];
-	return if !defined $valRow || !scalar keys %$valRow;
+	return 1 if !defined $valRow || !scalar keys %$valRow;
 
 	my $idx = 0;
 	foreach my $valRow (@$valRows) {
 		my $id      = $IDs->[$idx++];
 		my %valData = %$valRow;
-		delete $valData{'id'};
-		# filter column 'id' if present, as we don't want to update it
+		# fail if asked to change the column 'id', as that is bogus
+		return if exists $valData{id} && $valData{id} ne $id;
+		# filter column 'id' if present, as we don't want to write it
+		delete $valData{id};
 		my @cols = map { "$_ = " . $self->quote($valRow->{$_}) }
 		  grep { $_ ne 'id' }
 		  # filter column 'id' if present, as we don't want
 		  # to update it!
 		  keys %$valRow;
-		return if !@cols;
+		next if !@cols;
 		my $cols = join ', ', @cols;
 		my $sql = "UPDATE $table SET $cols";
 		if (defined $id) {
@@ -661,7 +716,26 @@ sub addSystem
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('system', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the systems to get the IDs ...
+	my @systemIDs = $self->_doInsert('system', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@systemIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setSystemAttrs($id, $attrs);
+	}
+
+	return @systemIDs;
 }
 
 sub removeSystem
@@ -678,37 +752,44 @@ sub changeSystem
 	my $systemIDs = shift;
 	my $valRows   = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$systemIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setSystemAttrs($id, $attrs);
+	}
+
+	# finally update all systems in one go
 	return $self->_doUpdate('system', $systemIDs, $valRows);
 }
 
-sub setSystemAttr
+sub setSystemAttrs
 {
-	my $self      = shift;
-	my $systemID  = shift;
-	my $attrName  = shift;
-	my $attrValue = shift;
-
-	my $quotedSystemID  = $self->{dbh}->quote($systemID);
-	my $quotedAttrName  = $self->{dbh}->quote($attrName);
-
-	my $sql = <<"	End-of-Here";
-		SELECT id FROM system_attr
-		WHERE system_id = $quotedSystemID
-		AND name = $quotedAttrName
-	End-of-Here
-	my $id = $self->_doSelect($sql, 'id');
-	if ($id) {
-		return $self->_doUpdate(
-			'system_attr', [ $id ], [ { value => $attrValue } ] 
+	my $self     = shift;
+	my $systemID = shift;
+	my $attrs    = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('system_attr', [ $systemID ], 'system_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'system_attr', [ {
+				system_id => $systemID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
 		);
 	}
-	return $self->_doInsert(
-		'system_attr', [ { 
-			system_id => $systemID,
-			name      => $attrName,
-			value     => $attrValue,
-		} ] 
-	);
+	return 1;
 }
 
 sub setClientIDsOfSystem
@@ -742,7 +823,26 @@ sub addClient
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('client', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the clients to get the IDs ...
+	my @clientIDs = $self->_doInsert('client', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@clientIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setClientAttrs($id, $attrs);
+	}
+
+	return @clientIDs;
 }
 
 sub removeClient
@@ -759,9 +859,46 @@ sub changeClient
 	my $clientIDs = shift;
 	my $valRows   = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$clientIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setClientAttrs($id, $attrs);
+	}
+
+	# finally update all systems in one go
 	return $self->_doUpdate('client', $clientIDs, $valRows);
 }
 
+sub setClientAttrs
+{
+	my $self     = shift;
+	my $clientID = shift;
+	my $attrs    = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('client_attr', [ $clientID ], 'client_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'client_attr', [ {
+				client_id => $clientID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
+		);
+	}
+	return 1;
+}
+
 sub setSystemIDsOfClient
 {
 	my $self      = shift;
@@ -793,7 +930,26 @@ sub addGroup
 	my $self    = shift;
 	my $valRows = shift;
 
-	return $self->_doInsert('groups', $valRows);
+	# separate the attribute hashes ...
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+
+	# ... store the groups to get the IDs ...
+	my @groupIDs = $self->_doInsert('groups', $valRows);
+
+	# ... finally store the individual attribute sets
+	foreach my $id (@groupIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setGroupAttrs($id, $attrs);
+	}
+
+	return @groupIDs;
 }
 
 sub removeGroup
@@ -810,9 +966,46 @@ sub changeGroup
 	my $groupIDs = shift;
 	my $valRows  = shift;
 
+	# separate the attribute hashes and store them individually
+	my @attrValRows 
+		=	map {
+				my $attrs = $_->{attrs};
+				delete $_->{attrs};
+				$attrs;
+			}
+			@$valRows;
+	foreach my $id (@$groupIDs) {
+		my $attrs = shift @attrValRows;
+		next if !defined $attrs;
+		return if !$self->setGroupAttrs($id, $attrs);
+	}
+
+	# finally update all groups in one go
 	return $self->_doUpdate('groups', $groupIDs, $valRows);
 }
 
+sub setGroupAttrs
+{
+	my $self    = shift;
+	my $groupID = shift;
+	my $attrs   = shift;
+
+	# we take the simple path and remove all attributes ...
+	return if !$self->_doDelete('group_attr', [ $groupID ], 'group_id');
+
+	# ... and (re-)insert the given ones
+	foreach my $key (keys %$attrs) {
+		return if !$self->_doInsert(
+			'group_attr', [ {
+				group_id => $groupID,
+				name      => $key,
+				value     => $attrs->{$key},
+			} ]
+		);
+	}
+	return 1;
+}
+
 sub setClientIDsOfGroup
 {
 	my $self      = shift;
@@ -896,6 +1089,16 @@ sub schemaFetchDBVersion
 	return $row->{schema_version};
 }
 
+sub schemaUpgradeDBFrom
+{
+	my $self        = shift;
+	my $currVersion = shift;
+
+	$self->_upgradeDBTo0_2() if $currVersion < 0.2;
+
+	return 1;
+}
+
 sub schemaSetDBVersion
 {
 	my $self      = shift;
@@ -1114,6 +1317,218 @@ sub schemaChangeColumns
 	return;
 }
 
+sub _upgradeDBTo0_2
+{
+	my $self = shift;
+
+	# move attributes into separate tables ...
+	#
+	# ... system attributes ...
+	$self->schemaAddTable(
+		'system_attr', 
+		[
+			'id:pk',
+			'system_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $system ($self->fetchSystemByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$system) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $system->{$key} || '';
+			next if $system->{id} > 0 && !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setSystemAttrs($system->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'system',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_ramfs_fsmods',
+			'attr_ramfs_miscmods',
+			'attr_ramfs_nicmods',
+			'attr_ramfs_screen',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'export_id:fk',
+			'name:s.64',
+			'label:s.64',
+			'kernel:s.128',
+			'kernel_params:s.512',
+			'hidden:b',
+			'comment:s.1024',
+		]
+	);
+	#
+	# ... client attributes ...
+	$self->schemaAddTable(
+		'client_attr',
+		[
+			'id:pk',
+			'client_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $client ($self->fetchClientByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$client) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $client->{$key} || '';
+			next if !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setClientAttrs($client->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'client',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'name:s.128',
+			'mac:s.20',
+			'boot_type:s.20',
+			'unbootable:b',
+			'kernel_params:s.128',
+			'comment:s.1024',
+		]
+	);
+	#
+	# ... group attributes ...
+	$self->schemaAddTable(
+		'group_attr',
+		[
+			'id:pk',
+			'group_id:fk',
+			'name:s.128',
+			'value:s.255',
+		]
+	);
+	foreach my $group ($self->fetchGroupByFilter()) {
+		my %attrs;
+		foreach my $key (keys %$group) {
+			next if substr($key, 0, 5) ne 'attr_';
+			my $attrValue = $group->{$key} || '';
+			next if !length($attrValue);
+			my $newAttrName = substr($key, 5);
+			$attrs{$newAttrName} = $attrValue;
+		}
+		$self->setGroupAttrs($group->{id}, \%attrs);
+	}
+	$self->schemaDropColumns(
+		'groups',
+		[
+			'attr_automnt_dir',
+			'attr_automnt_src',
+			'attr_country',
+			'attr_dm_allow_shutdown',
+			'attr_hw_graphic',
+			'attr_hw_monitor',
+			'attr_hw_mouse',
+			'attr_late_dm',
+			'attr_netbios_workgroup',
+			'attr_nis_domain',
+			'attr_nis_servers',
+			'attr_sane_scanner',
+			'attr_scratch',
+			'attr_slxgrp',
+			'attr_start_alsasound',
+			'attr_start_atd',
+			'attr_start_cron',
+			'attr_start_dreshal',
+			'attr_start_ntp',
+			'attr_start_nfsv4',
+			'attr_start_printer',
+			'attr_start_samba',
+			'attr_start_snmp',
+			'attr_start_sshd',
+			'attr_start_syslog',
+			'attr_start_x',
+			'attr_start_xdmcp',
+			'attr_tex_enable',
+			'attr_timezone',
+			'attr_tvout',
+			'attr_vmware',
+		],
+		[
+			'id:pk',
+			'name:s.128',
+			'priority:i',
+			'comment:s.1024',
+		]
+	);
+
+	return 1;
+}
+
 1;
 
 =head1 NAME
diff --git a/config-db/slxconfig b/config-db/slxconfig
index 95019e3b..6df489ca 100755
--- a/config-db/slxconfig
+++ b/config-db/slxconfig
@@ -66,18 +66,24 @@ my $openslxDB = OpenSLX::ConfigDB->new();
 $openslxDB->connect();
 
 my $action = shift @ARGV || '';
-if ($action =~ m[^add-s]i) {
-	addSystemToConfigDB(@ARGV);
-}
-elsif ($action =~ m[^add-c]i) {
+if ($action =~ m[^add-c]i) {
 	addClientToConfigDB(@ARGV);
 }
+elsif ($action =~ m[^add-g]i) {
+	addGroupToConfigDB(@ARGV);
+}
+elsif ($action =~ m[^add-s]i) {
+	addSystemToConfigDB(@ARGV);
+}
 elsif ($action =~ m[^change-v]i) {
 	changeVendorOSInConfigDB(@ARGV);
 }
 elsif ($action =~ m[^change-e]i) {
 	changeExportInConfigDB(@ARGV);
 }
+elsif ($action =~ m[^change-g]i) {
+	changeGroupInConfigDB(@ARGV);
+}
 elsif ($action =~ m[^change-s]i) {
 	changeSystemInConfigDB(@ARGV);
 }
@@ -112,6 +118,10 @@ elsif ($action =~ m[^search-e]) {
 	print _tr("Matching exports:\n");
 	searchExports(@ARGV);
 }
+elsif ($action =~ m[^search-g]) {
+	print _tr("Matching groups:\n");
+	searchGroups(@ARGV);
+}
 elsif ($action =~ m[^search-s]) {
 	print _tr("Matching systems:\n");
 	searchSystems(@ARGV);
@@ -120,10 +130,13 @@ elsif ($action =~ m[^search-v]) {
 	print _tr("Matching vendor-OSes:\n");
 	searchVendorOSes(@ARGV);
 }
-elsif ($action =~ m[^remove-cli]i) {
+elsif ($action =~ m[^remove-c]i) {
 	removeClientFromConfigDB(@ARGV);
 }
-elsif ($action =~ m[^remove-sys]i) {
+elsif ($action =~ m[^remove-g]i) {
+	removeClientFromConfigDB(@ARGV);
+}
+elsif ($action =~ m[^remove-s]i) {
 	removeSystemFromConfigDB(@ARGV);
 }
 else {
@@ -227,7 +240,7 @@ sub dumpElements
 			print join(
 				'',
 				map {
-					my $elemVal = $elem->{$_} || '';
+					my $elemVal = defined $elem->{$_} ? $elem->{$_} : '-';
 					if (ref($elemVal) eq 'HASH') {
 						my $spcLen 
 							= max(map { length($_) } keys %$elemVal) || 0;
@@ -237,7 +250,7 @@ sub dumpElements
 							map {
 								my $spc = ' ' x $spcLen;
 								my $val = $elemVal->{$_} || '';
-								$val =~ s[\n][\n\t$spc   ]g;
+								$val =~ s[\n][\n$ind$spc   ]g;
 								"$ind$_" . substr($spc, length($_)) . " = $val";
 							}
 							sort keys %$elemVal
@@ -246,7 +259,7 @@ sub dumpElements
 						"  $_:\n$subLines\n";
 					} else {
 						my $spc = ' ' x $spcLen;
-						$elemVal =~ s[\n][\n\t$spc   ]g;
+						$elemVal =~ s[\n][\n$ind$spc   ]g;
 						"$ind$_" . substr($spc, length($_)) . " = $elemVal\n";
 					}
 				}
@@ -285,6 +298,9 @@ sub listClients
 					map { $_->{name} }
 					sort { $a->{name} cmp $b->{name} }
 					$openslxDB->fetchSystemByID(\@sysIDs, 'name');
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} } 
@@ -319,6 +335,9 @@ sub listGroups
 				=	join "\n", map { $_->{name} }
 					sort { $a->{name} cmp $b->{name} }
 					$openslxDB->fetchClientByID(\@clientIDs, 'name');
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} } 
@@ -387,7 +406,9 @@ sub listSystems
 			if (defined $export) {
 				$_->{export_id} = "$export->{name} ($export->{type})";
 			}
-			$_->{ATTRIBUTES} = $openslxDB->fetchSystemAttrsAsHash($_->{id});
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} }
@@ -419,7 +440,10 @@ sub listVendorOSes
 sub searchClients
 {
 	my @clientKeys = $openslxDB->getColumnsOfTable('client');
-	my $clientData = parseKeyValueArgs(\@clientKeys, 'client', @_);
+	my @clientAttrKeys = $openslxDB->getKnownClientAttrs();
+	my ($clientData, $clientAttrs) = parseKeyValueArgsWithAttrs(
+		\@clientKeys, \@clientAttrKeys, 'client', @_
+	);
 
 	# set verbose mode if any params have been passed in:
 	$verbose = 1 if %$clientData;
@@ -432,10 +456,13 @@ sub searchClients
 				=	join "\n", map { $_->{name} }
 					sort { $a->{name} cmp $b->{name} }
 					$openslxDB->fetchSystemByID(\@sysIDs, 'name');
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} }
-		$openslxDB->fetchClientByFilter($clientData)
+		$openslxDB->fetchClientByFilter($clientData, undef, $clientAttrs)
 	);
 
 	return 1;
@@ -444,7 +471,10 @@ sub searchClients
 sub searchGroups
 {
 	my @groupKeys = $openslxDB->getColumnsOfTable('groups');
-	my $groupData = parseKeyValueArgs(\@groupKeys, 'groups', @_);
+	my @groupAttrKeys = $openslxDB->getKnownClientAttrs();
+	my ($groupData, $groupAttrs) = parseKeyValueArgsWithAttrs(
+		\@groupKeys, \@groupAttrKeys, 'group', @_
+	);
 
 	# set verbose mode if any params have been passed in:
 	$verbose = 1 if %$groupData;
@@ -462,10 +492,13 @@ sub searchGroups
 				=	join "\n", map { $_->{name} }
 					sort { $a->{name} cmp $b->{name} }
 					$openslxDB->fetchClientByID(\@clientIDs, 'name');
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} }
-		$openslxDB->fetchGroupByFilter($groupData)
+		$openslxDB->fetchGroupByFilter($groupData, undef, $groupAttrs)
 	);
 
 	return 1;
@@ -523,7 +556,9 @@ sub searchSystems
 			if (defined $export) {
 				$_->{export_id} = "$export->{name} ($export->{type})";
 			}
-			$_->{ATTRIBUTES} = $openslxDB->fetchSystemAttrsAsHash($_->{id});
+			# rename attrs to ATTRIBUTES for display
+			$_->{ATTRIBUTES} = $_->{attrs};
+			delete $_->{attrs};
 			$_;
 		}
 		sort { $a->{name} cmp $b->{name} }
diff --git a/config-db/t/01-basics.t b/config-db/t/01-basics.t
index fdc7a052..903783c4 100644
--- a/config-db/t/01-basics.t
+++ b/config-db/t/01-basics.t
@@ -5,6 +5,9 @@ use lib '/opt/openslx/lib';
 # basic stuff
 use_ok(OpenSLX::ConfigDB);
 
+use strict;
+use warnings;
+
 # connecting and disconnecting
 ok(my $configDB = OpenSLX::ConfigDB->new, 'can create object');
 isa_ok($configDB, 'OpenSLX::ConfigDB');
diff --git a/config-db/t/10-vendor-os.t b/config-db/t/10-vendor-os.t
index b0754be7..04aa4f2e 100644
--- a/config-db/t/10-vendor-os.t
+++ b/config-db/t/10-vendor-os.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -176,6 +179,9 @@ ok(
 is($vendorOS1->{id},   1,          'really got vendor-OS number 1');
 is($vendorOS1->{name}, q{VOS-'1'}, q{really got vendor-OS named "VOS-'1'"});
 
+# changing nothing at all should succeed
+ok($configDB->changeVendorOS(1), 'changing nothing at all in vendor-OS 1');
+
 # changing a non-existing column should fail
 ok(
 	! eval { $configDB->changeVendorOS(1, { xname => "xx" }) }, 
diff --git a/config-db/t/11-export.t b/config-db/t/11-export.t
index 96fad00b..0cdc688c 100644
--- a/config-db/t/11-export.t
+++ b/config-db/t/11-export.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -223,6 +226,9 @@ ok(
 is($export1->{id},   1,          'really got export number 1');
 is($export1->{name}, q{EXP-'1'}, q{really got export named "EXP-'1'"});
 
+# changing nothing at all should succeed
+ok($configDB->changeExport(1), 'changing nothing at all in export 1');
+
 # changing a non-existing column should fail
 ok(
 	! eval { $configDB->changeExport(1, { xname => "xx" }) }, 
diff --git a/config-db/t/12-system.t b/config-db/t/12-system.t
index ee908dba..7a3e5e1e 100644
--- a/config-db/t/12-system.t
+++ b/config-db/t/12-system.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -35,6 +38,11 @@ my $inSystem1 = {
 	'name'      => 'sys-1',
 	'export_id' => 1,
 	'comment'   => '',
+	'attrs'     => {
+		'ramfs_fsmods'  => 'squashfs',
+		'ramfs_nicmods' => 'e1000 forcedeth r8169',
+		'start_sshd'    => 'yes',
+	},
 };
 is(
 	my $system1ID = $configDB->addSystem($inSystem1), 1,
@@ -55,10 +63,43 @@ my $fullSystem = {
 	'label'               => 'BlingBling System - really kuul!',
 	'kernel_params'       => 'debug=3 console=ttyS1',
 	'hidden'              => '1',
-	'attr_ramfs_nicmods'  => 'e1000 forcedeth',
-	'attr_ramfs_fsmods'   => 'squashfs',
-	'attr_ramfs_miscmods' => 'tpm',
-	'attr_ramfs_screen'   => '1024x768',
+	'attrs' => {
+		'automnt_dir'       => 'a',
+		'automnt_src'       => 'b',
+		'country'           => 'c',
+		'dm_allow_shutdown' => 'd',
+		'hw_graphic'        => 'e',
+		'hw_monitor'        => 'f',
+		'hw_mouse'          => 'g',
+		'late_dm'           => 'h',
+		'netbios_workgroup' => 'i',
+		'nis_domain'        => 'j',
+		'nis_servers'       => 'k',
+		'ramfs_fsmods'      => 'l',
+		'ramfs_miscmods'    => 'm',
+		'ramfs_nicmods'     => 'n',
+		'ramfs_screen'      => 'o',
+		'sane_scanner'      => 'p',
+		'scratch'           => 'q',
+		'slxgrp'            => 'r',
+		'start_alsasound'   => 's',
+		'start_atd'         => 't',
+		'start_cron'        => 'u',
+		'start_dreshal'     => 'v',
+		'start_ntp'         => 'w',
+		'start_nfsv4'       => 'x',
+		'start_printer'     => 'y',
+		'start_samba'       => 'z',
+		'start_snmp'        => 'A',
+		'start_sshd'        => 'B',
+		'start_syslog'      => 'C',
+		'start_x'           => 'D',
+		'start_xdmcp'       => 'E',
+		'tex_enable'        => 'F',
+		'timezone'          => 'G',
+		'tvout'             => 'H',
+		'vmware'            => 'I',
+	},
 };
 ok(
 	my ($system2ID, $system3ID) = $configDB->addSystem([
@@ -79,39 +120,72 @@ is($system3->{comment},             'nuff said',             'system 3 - comment
 is($system3->{label},               'BlingBling System - really kuul!', 'system 3 - label');
 is($system3->{kernel_params},       'debug=3 console=ttyS1', 'system 3 - kernel_params');
 is($system3->{hidden},              '1',                     'system 3 - hidden');
-is($system3->{attr_ramfs_nicmods},  'e1000 forcedeth',       'system 3 - attr_ramfs_nicmods');
-is($system3->{attr_ramfs_fsmods},   'squashfs',              'system 3 - attr_ramfs_fsmods');
-is($system3->{attr_ramfs_miscmods}, 'tpm',                   'system 3 - attr_ramfs_miscmods');
-is($system3->{attr_ramfs_screen},   '1024x768',              'system 3 - attr_ramfs_screen');
+is($system3->{attrs}->{automnt_dir},       'a',              'system 3 - attr automnt_dir');
+is($system3->{attrs}->{automnt_src},       'b',              'system 3 - attr automnt_src');
+is($system3->{attrs}->{country},           'c',              'system 3 - attr country');
+is($system3->{attrs}->{dm_allow_shutdown}, 'd',              'system 3 - attr dm_allow_shutdown');
+is($system3->{attrs}->{hw_graphic},        'e',              'system 3 - attr hw_graphic');
+is($system3->{attrs}->{hw_monitor},        'f',              'system 3 - attr hw_monitor');
+is($system3->{attrs}->{hw_mouse},          'g',              'system 3 - attr hw_mouse');
+is($system3->{attrs}->{late_dm},           'h',              'system 3 - attr late_dm');
+is($system3->{attrs}->{netbios_workgroup}, 'i',              'system 3 - attr netbios_workgroup');
+is($system3->{attrs}->{nis_domain},        'j',              'system 3 - attr nis_domain');
+is($system3->{attrs}->{nis_servers},       'k',              'system 3 - attr nis_servers');
+is($system3->{attrs}->{ramfs_fsmods},      'l',              'system 3 - attr ramfs_fsmods');
+is($system3->{attrs}->{ramfs_miscmods},    'm',              'system 3 - attr ramfs_miscmods');
+is($system3->{attrs}->{ramfs_nicmods},     'n',              'system 3 - attr ramfs_nicmods');
+is($system3->{attrs}->{ramfs_screen},      'o',              'system 3 - attr ramfs_screen');
+is($system3->{attrs}->{sane_scanner},      'p',              'system 3 - attr sane_scanner');
+is($system3->{attrs}->{scratch},           'q',              'system 3 - attr scratch');
+is($system3->{attrs}->{slxgrp},            'r',              'system 3 - attr slxgrp');
+is($system3->{attrs}->{start_alsasound},   's',              'system 3 - attr start_alsasound');
+is($system3->{attrs}->{start_atd},         't',              'system 3 - attr start_atd');
+is($system3->{attrs}->{start_cron},        'u',              'system 3 - attr start_cron');
+is($system3->{attrs}->{start_dreshal},     'v',              'system 3 - attr start_dreshal');
+is($system3->{attrs}->{start_ntp},         'w',              'system 3 - attr start_ftp');
+is($system3->{attrs}->{start_nfsv4},       'x',              'system 3 - attr start_nfsv4');
+is($system3->{attrs}->{start_printer},     'y',              'system 3 - attr start_printer');
+is($system3->{attrs}->{start_samba},       'z',              'system 3 - attr start_samba');
+is($system3->{attrs}->{start_snmp},        'A',              'system 3 - attr start_snmp');
+is($system3->{attrs}->{start_sshd},        'B',              'system 3 - attr start_sshd');
+is($system3->{attrs}->{start_syslog},      'C',              'system 3 - attr start_syslog');
+is($system3->{attrs}->{start_x},           'D',              'system 3 - attr start_x');
+is($system3->{attrs}->{start_xdmcp},       'E',              'system 3 - attr start_xdmcp');
+is($system3->{attrs}->{tex_enable},        'F',              'system 3 - attr tex_enable');
+is($system3->{attrs}->{timezone},          'G',              'system 3 - attr timezone');
+is($system3->{attrs}->{tvout},             'H',              'system 3 - attr tvout');
+is($system3->{attrs}->{vmware},            'I',              'system 3 - attr vmware');
+is(keys %{$system3->{attrs}},              35,               'system 3 - attribute count');
 
 # fetch system 2 by a filter on id and check all values
 ok(
 	my $system2 = $configDB->fetchSystemByFilter({ id => 2 }), 
 	'fetch system 2 by filter on id'
 );
-is($system2->{id},        2,         'system 2 - id');
-is($system2->{name},      'sys-2.0', 'system 2 - name');
-is($system2->{kernel},    'vmlinuz', 'system 2 - kernel');
-is($system2->{export_id}, '1',       'system 2 - export_id');
-is($system2->{comment},   undef,     'system 2 - comment');
+is($system2->{id},            2,         'system 2 - id');
+is($system2->{name},          'sys-2.0', 'system 2 - name');
+is($system2->{kernel},        'vmlinuz', 'system 2 - kernel');
+is($system2->{export_id},     '1',       'system 2 - export_id');
+is($system2->{comment},       undef,     'system 2 - comment');
+is(keys %{$system2->{attrs}}, 0,         'system 2 - attribute count');
 
 # fetch system 1 by filter on name and check all values
 ok(
 	my $system1 = $configDB->fetchSystemByFilter({ name => 'sys-1' }), 
 	'fetch system 1 by filter on name'
 );
-is($system1->{id},                  1,         'system 1 - id');
-is($system1->{name},                'sys-1',   'system 1 - name');
-is($system1->{export_id},           '1',       'system 1 - export_id');
-is($system1->{kernel},              'vmlinuz', 'system 1 - kernel');
-is($system1->{comment},             '',        'system 1 - comment');
-is($system1->{label},               'sys-1',   'system 1 - label');
-is($system1->{kernel_params},       undef,     'system 1 - kernel_params');
-is($system1->{hidden},              undef,     'system 1 - hidden');
-is($system1->{attr_ramfs_nicmods},  undef,     'system 1 - attr_ramfs_nicmods');
-is($system1->{attr_ramfs_fsmods},   undef,     'system 1 - attr_ramfs_fsmods');
-is($system1->{attr_ramfs_miscmods}, undef,     'system 1 - attr_ramfs_miscmods');
-is($system1->{attr_ramfs_screen},   undef,     'system 1 - attr_ramfs_screen');
+is($system1->{id},            1,         'system 1 - id');
+is($system1->{name},          'sys-1',   'system 1 - name');
+is($system1->{export_id},     '1',       'system 1 - export_id');
+is($system1->{kernel},        'vmlinuz', 'system 1 - kernel');
+is($system1->{comment},       '',        'system 1 - comment');
+is($system1->{label},         'sys-1',   'system 1 - label');
+is($system1->{kernel_params}, undef,     'system 1 - kernel_params');
+is($system1->{hidden},        undef,     'system 1 - hidden');
+is(keys %{$system1->{attrs}}, 3,         'system 1 - attribute count');
+is($system1->{attrs}->{ramfs_fsmods},   'squashfs',              'system 1 - attr ramfs_fsmods');
+is($system1->{attrs}->{ramfs_nicmods},  'e1000 forcedeth r8169', 'system 1 - attr ramfs_nicmods');
+is($system1->{attrs}->{start_sshd},     'yes',                   'system 1 - attr start_sshd');
 
 # fetch systems 3 & 1 by id
 ok(
@@ -148,6 +222,17 @@ is(@systems1And2, 2, 'should have got 2 systems');
 is($systems1And2[0]->{id}, 1, 'first id should be 1');
 is($systems1And2[1]->{id}, 2, 'second id should be 2');
 
+# fetch systems 1 & 2 by filter on hidden being undef'd
+ok(
+	@systems1And2 = $configDB->fetchSystemByFilter({ hidden => undef }), 
+	'fetch systems 1 & 2 by filter on hidden being undefined'
+);
+is(@systems1And2, 2, 'should have got 2 systems');
+# now sort by ID and check if we have really got 1 and 2
+@systems1And2 = sort { $a->{id} cmp $b->{id} } @systems1And2;
+is($systems1And2[0]->{id}, 1, 'first id should be 1');
+is($systems1And2[1]->{id}, 2, 'second id should be 2');
+
 # try to fetch with multi-column filter
 ok(
 	($system2, $system3)
@@ -169,6 +254,83 @@ is(@systems1And3, 2, 'should have got 2 systems');
 is($systems1And3[0]->{id}, 1, 'first id should be 1');
 is($systems1And3[1]->{id}, 3, 'second id should be 3');
 
+# filter systems by different attributes & values in combination
+ok( 
+	my @system1Only = $configDB->fetchSystemByFilter( {}, undef, { 
+		ramfs_nicmods => 'e1000 forcedeth r8169'
+	} ),
+	'fetch system 1 by filter on attribute ramfs_nicmods'
+);
+
+is(@system1Only, 1, 'should have got 1 system');
+is($system1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@system1Only = $configDB->fetchSystemByFilter( undef, 'id', { 
+		ramfs_nicmods => 'e1000 forcedeth r8169',
+		slxgrp        => undef,
+	} ),
+	'fetch system 1 by filter on attribute ramfs_nicmods'
+);
+is(@system1Only, 1, 'should have got 1 system');
+is($system1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@system1Only = $configDB->fetchSystemByFilter( {
+		export_id => 1,
+		hidden    => undef,
+	}, 'id', {
+		ramfs_nicmods => 'e1000 forcedeth r8169',
+		slxgrp        => undef,
+	} ),
+	'fetch system 1 by multiple filter on values and attributes'
+);
+is(@system1Only, 1, 'should have got 1 system');
+is($system1Only[0]->{id}, 1, 'first id should be 1');
+
+is(
+	$configDB->fetchSystemByFilter( {
+		export_id => 2,
+	}, 'id', {
+		ramfs_nicmods => 'e1000 forcedeth r8169',
+		slxgrp        => undef,
+	} ),
+	undef,
+	'mismatch system 1 by filter with incorrect value'
+);
+is(
+	$configDB->fetchSystemByFilter( {
+		export_id => 1,
+	}, 'id', {
+		ramfs_nicmods => 'xxxx',
+		slxgrp        => undef,
+	} ),
+	undef,
+	'mismatch system 1 by filter with incorrect attribute value'
+);
+is(
+	$configDB->fetchSystemByFilter( {
+		name      => 'sys-1',
+	}, 'id', {
+		start_sshd => undef,
+	} ),
+	undef,
+	'mismatch system 1 by filter with attribute not being empty'
+);
+
+# fetch systems 1 & 2 by filter on attribute start_samba not existing
+ok(
+	@systems1And2 = $configDB->fetchSystemByFilter( {}, undef, {
+		start_samba => undef,
+	} ), 
+	'fetch systems 1 & 2 by filter on attribute start_samba not existing'
+);
+is(@systems1And2, 2, 'should have got 2 systems');
+# now sort by ID and check if we have really got 1 and 2
+@systems1And2 = sort { $a->{id} cmp $b->{id} } @systems1And2;
+is($systems1And2[0]->{id}, 1, 'first id should be 1');
+is($systems1And2[1]->{id}, 2, 'second id should be 2');
+
 # try to fetch a couple of non-existing systems by id
 is(
 	$configDB->fetchSystemByID(-1), undef, 
@@ -203,6 +365,9 @@ ok(
 is($system1->{id},   1,          'really got system number 1');
 is($system1->{name}, q{SYS-'1'}, q{really got system named "SYS-'1'"});
 
+# changing nothing at all should succeed
+ok($configDB->changeSystem(1), 'changing nothing at all in system 1');
+
 # changing a non-existing column should fail
 ok(
 	! eval { $configDB->changeSystem(1, { xname => "xx" }) }, 
diff --git a/config-db/t/13-client.t b/config-db/t/13-client.t
index 70ed569c..5848ba53 100644
--- a/config-db/t/13-client.t
+++ b/config-db/t/13-client.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -35,6 +38,11 @@ my $inClient1 = {
 	'name'    => 'cli-1',
 	'mac'     => '01:02:03:04:05:01',
 	'comment' => '',
+	'attrs'     => {
+		'slxgrp'     => 'slxgrp',
+		'start_snmp' => 'no',
+		'start_sshd' => 'yes',
+	},
 };
 is(
 	my $client1ID = $configDB->addClient($inClient1), 1,
@@ -55,6 +63,39 @@ my $fullClient = {
 	'kernel_params' => 'debug=3 console=ttyS1',
 	'unbootable'    => '0',
 	'boot_type'     => 'pxe',
+	'attrs' => {
+		'automnt_dir'       => 'a',
+		'automnt_src'       => 'b',
+		'country'           => 'c',
+		'dm_allow_shutdown' => 'd',
+		'hw_graphic'        => 'e',
+		'hw_monitor'        => 'f',
+		'hw_mouse'          => 'g',
+		'late_dm'           => 'h',
+		'netbios_workgroup' => 'i',
+		'nis_domain'        => 'j',
+		'nis_servers'       => 'k',
+		'sane_scanner'      => 'p',
+		'scratch'           => 'q',
+		'slxgrp'            => 'r',
+		'start_alsasound'   => 's',
+		'start_atd'         => 't',
+		'start_cron'        => 'u',
+		'start_dreshal'     => 'v',
+		'start_ntp'         => 'w',
+		'start_nfsv4'       => 'x',
+		'start_printer'     => 'y',
+		'start_samba'       => 'z',
+		'start_snmp'        => 'A',
+		'start_sshd'        => 'B',
+		'start_syslog'      => 'C',
+		'start_x'           => 'D',
+		'start_xdmcp'       => 'E',
+		'tex_enable'        => 'F',
+		'timezone'          => 'G',
+		'tvout'             => 'H',
+		'vmware'            => 'I',
+	},
 };
 ok(
 	my ($client2ID, $client3ID) = $configDB->addClient([
@@ -74,18 +115,51 @@ is($client3->{comment},       'nuff said',             'client 3 - comment');
 is($client3->{boot_type},     'pxe',                   'client 3 - boot_type');
 is($client3->{kernel_params}, 'debug=3 console=ttyS1', 'client 3 - kernel_params');
 is($client3->{unbootable},    '0',                     'client 3 - unbootable');
+is($client3->{attrs}->{automnt_dir},       'a',              'client 3 - attr automnt_dir');
+is($client3->{attrs}->{automnt_src},       'b',              'client 3 - attr automnt_src');
+is($client3->{attrs}->{country},           'c',              'client 3 - attr country');
+is($client3->{attrs}->{dm_allow_shutdown}, 'd',              'client 3 - attr dm_allow_shutdown');
+is($client3->{attrs}->{hw_graphic},        'e',              'client 3 - attr hw_graphic');
+is($client3->{attrs}->{hw_monitor},        'f',              'client 3 - attr hw_monitor');
+is($client3->{attrs}->{hw_mouse},          'g',              'client 3 - attr hw_mouse');
+is($client3->{attrs}->{late_dm},           'h',              'client 3 - attr late_dm');
+is($client3->{attrs}->{netbios_workgroup}, 'i',              'client 3 - attr netbios_workgroup');
+is($client3->{attrs}->{nis_domain},        'j',              'client 3 - attr nis_domain');
+is($client3->{attrs}->{nis_servers},       'k',              'client 3 - attr nis_servers');
+is($client3->{attrs}->{sane_scanner},      'p',              'client 3 - attr sane_scanner');
+is($client3->{attrs}->{scratch},           'q',              'client 3 - attr scratch');
+is($client3->{attrs}->{slxgrp},            'r',              'client 3 - attr slxgrp');
+is($client3->{attrs}->{start_alsasound},   's',              'client 3 - attr start_alsasound');
+is($client3->{attrs}->{start_atd},         't',              'client 3 - attr start_atd');
+is($client3->{attrs}->{start_cron},        'u',              'client 3 - attr start_cron');
+is($client3->{attrs}->{start_dreshal},     'v',              'client 3 - attr start_dreshal');
+is($client3->{attrs}->{start_ntp},         'w',              'client 3 - attr start_ftp');
+is($client3->{attrs}->{start_nfsv4},       'x',              'client 3 - attr start_nfsv4');
+is($client3->{attrs}->{start_printer},     'y',              'client 3 - attr start_printer');
+is($client3->{attrs}->{start_samba},       'z',              'client 3 - attr start_samba');
+is($client3->{attrs}->{start_snmp},        'A',              'client 3 - attr start_snmp');
+is($client3->{attrs}->{start_sshd},        'B',              'client 3 - attr start_sshd');
+is($client3->{attrs}->{start_syslog},      'C',              'client 3 - attr start_syslog');
+is($client3->{attrs}->{start_x},           'D',              'client 3 - attr start_x');
+is($client3->{attrs}->{start_xdmcp},       'E',              'client 3 - attr start_xdmcp');
+is($client3->{attrs}->{tex_enable},        'F',              'client 3 - attr tex_enable');
+is($client3->{attrs}->{timezone},          'G',              'client 3 - attr timezone');
+is($client3->{attrs}->{tvout},             'H',              'client 3 - attr tvout');
+is($client3->{attrs}->{vmware},            'I',              'client 3 - attr vmware');
+is(keys %{$client3->{attrs}},              31,               'client 3 - attribute count');
 
 # fetch client 2 by a filter on id and check all values
 ok(
 	my $client2 = $configDB->fetchClientByFilter({ id => 2 }), 
 	'fetch client 2 by filter on id'
 );
-is($client2->{id},         2,                   'client 2 - id');
-is($client2->{name},       'cli-2.0',           'client 2 - name');
-is($client2->{unbootable}, '1',                 'client 2 - unbootable');
-is($client2->{mac},        '01:02:03:04:05:02', 'client 2 - mac');
-is($client2->{comment},    undef,               'client 2 - comment');
-is($client2->{boot_type},  'etherboot',         'client 2 - boot_type');
+is($client2->{id},            2,                   'client 2 - id');
+is($client2->{name},          'cli-2.0',           'client 2 - name');
+is($client2->{unbootable},    '1',                 'client 2 - unbootable');
+is($client2->{mac},           '01:02:03:04:05:02', 'client 2 - mac');
+is($client2->{comment},       undef,               'client 2 - comment');
+is($client2->{boot_type},     'etherboot',         'client 2 - boot_type');
+is(keys %{$client2->{attrs}}, 0,                   'client 2 - attribute count');
 
 # fetch client 1 by filter on name and check all values
 ok(
@@ -99,6 +173,10 @@ is($client1->{unbootable},    undef,               'client 1 - unbootable');
 is($client1->{comment},       '',                  'client 1 - comment');
 is($client1->{boot_type},     'pxe',               'client 1 - boot_type');
 is($client1->{kernel_params}, undef,               'client 1 - kernel_params');
+is(keys %{$client1->{attrs}}, 3,                   'client 1 - attribute count');
+is($client1->{attrs}->{slxgrp},     'slxgrp',      'client 1 - attr slxgrp');
+is($client1->{attrs}->{start_snmp}, 'no',          'client 1 - attr start_snmp');
+is($client1->{attrs}->{start_sshd}, 'yes',         'client 1 - attr start_sshd');
 
 # fetch clients 3 & 1 by id
 ok(
@@ -144,6 +222,14 @@ ok(
 is($client1->{name}, 'cli-1', 'should have got cli-1');
 is($client3, undef, 'should not get cli-nr-3');
 
+# fetch client 1 by filter on unbootable being undef'd
+ok(
+	my @client1Only = $configDB->fetchClientByFilter({ unbootable => undef }), 
+	'fetch client 1 by filter on unbootable being undefined'
+);
+is(@client1Only, 1, 'should have got 1 client');
+is($client1Only[0]->{id}, 1, 'first id should be 1');
+
 # try to fetch multiple occurrences of the same client, combined with
 # some unknown IDs
 ok(
@@ -156,6 +242,84 @@ is(@clients1And3, 2, 'should have got 2 clients');
 is($clients1And3[0]->{id}, 1, 'first id should be 1');
 is($clients1And3[1]->{id}, 3, 'second id should be 3');
 
+# filter clients by different attributes & values in combination
+ok( 
+	@client1Only = $configDB->fetchClientByFilter( {}, undef, { 
+		start_snmp => 'no',
+	} ),
+	'fetch client 1 by filter on attribute start_snmp'
+);
+
+is(@client1Only, 1, 'should have got 1 client');
+is($client1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@client1Only = $configDB->fetchClientByFilter( undef, 'id', { 
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	'fetch client 1 by filter on attribute start_snmp + non-existing attr'
+);
+is(@client1Only, 1, 'should have got 1 client');
+is($client1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@client1Only = $configDB->fetchClientByFilter( {
+		name       => 'cli-1',
+		unbootable => undef,
+	}, 'id', {
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	'fetch client 1 by multiple filter on values and attributes'
+);
+is(@client1Only, 1, 'should have got 1 client');
+is($client1Only[0]->{id}, 1, 'first id should be 1');
+
+is(
+	$configDB->fetchClientByFilter( {
+		comment => 'xxx',
+	}, 'id', {
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	undef,
+	'mismatch client 1 by filter with incorrect value'
+);
+is(
+	$configDB->fetchClientByFilter( {
+		name => 'cli-1',
+	}, 'id', {
+		start_snmp => 'yes',
+		tex_enable => undef,
+	} ),
+	undef,
+	'mismatch client 1 by filter with incorrect attribute value'
+);
+is(
+	$configDB->fetchClientByFilter( {
+		name => 'cli-1',
+	}, 'id', {
+		start_sshd => undef,
+	} ),
+	undef,
+	'mismatch client 1 by filter with attribute not being empty'
+);
+
+# fetch clients 0, 1 & 2 by filter on attribute start_samba not existing
+ok(
+	my @clients01And2 = $configDB->fetchClientByFilter( {}, undef, {
+		start_samba => undef,
+	} ), 
+	'fetch clients 0,1 & 2 by filter on attribute start_samba not existing'
+);
+is(@clients01And2, 3, 'should have got 3 clients');
+# now sort by ID and check if we have really got 0, 1 and 2
+@clients01And2 = sort { $a->{id} cmp $b->{id} } @clients01And2;
+is($clients01And2[0]->{id}, 0, 'first id should be 0');
+is($clients01And2[1]->{id}, 1, 'second id should be 1');
+is($clients01And2[2]->{id}, 2, 'third id should be 2');
+
 # try to fetch a couple of non-existing clients by id
 is(
 	$configDB->fetchClientByID(-1), undef, 
@@ -190,6 +354,9 @@ ok(
 is($client1->{id},   1,          'really got client number 1');
 is($client1->{name}, q{CLI-'1'}, q{really got client named "CLI-'1'"});
 
+# changing nothing at all should succeed
+ok($configDB->changeClient(1), 'changing nothing at all in client 1');
+
 # changing a non-existing column should fail
 ok(
 	! eval { $configDB->changeClient(1, { xname => "xx" }) }, 
diff --git a/config-db/t/14-group.t b/config-db/t/14-group.t
index 70831a5e..59530257 100644
--- a/config-db/t/14-group.t
+++ b/config-db/t/14-group.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -34,6 +37,11 @@ is(
 my $inGroup1 = {
 	'name'     => 'grp-1',
 	'comment'  => '',
+	'attrs'     => {
+		'slxgrp'     => 'slxgrp',
+		'start_snmp' => 'no',
+		'start_sshd' => 'yes',
+	},
 };
 is(
 	my $group1ID = $configDB->addGroup($inGroup1), 1,
@@ -49,6 +57,39 @@ my $fullGroup = {
 	'name'     => 'grp-nr-3',
 	'priority' => 50,
 	'comment'  => 'nuff said',
+	'attrs' => {
+		'automnt_dir'       => 'a',
+		'automnt_src'       => 'b',
+		'country'           => 'c',
+		'dm_allow_shutdown' => 'd',
+		'hw_graphic'        => 'e',
+		'hw_monitor'        => 'f',
+		'hw_mouse'          => 'g',
+		'late_dm'           => 'h',
+		'netbios_workgroup' => 'i',
+		'nis_domain'        => 'j',
+		'nis_servers'       => 'k',
+		'sane_scanner'      => 'p',
+		'scratch'           => 'q',
+		'slxgrp'            => 'r',
+		'start_alsasound'   => 's',
+		'start_atd'         => 't',
+		'start_cron'        => 'u',
+		'start_dreshal'     => 'v',
+		'start_ntp'         => 'w',
+		'start_nfsv4'       => 'x',
+		'start_printer'     => 'y',
+		'start_samba'       => 'z',
+		'start_snmp'        => 'A',
+		'start_sshd'        => 'B',
+		'start_syslog'      => 'C',
+		'start_x'           => 'D',
+		'start_xdmcp'       => 'E',
+		'tex_enable'        => 'F',
+		'timezone'          => 'G',
+		'tvout'             => 'H',
+		'vmware'            => 'I',
+	},
 };
 ok(
 	my ($group2ID, $group3ID) = $configDB->addGroup([
@@ -61,10 +102,42 @@ is($group3ID, 3, 'group 3 should have ID=3');
 
 # fetch group 3 by id and check all values
 ok(my $group3 = $configDB->fetchGroupByID(3), 'fetch group 3');
-is($group3->{id},       '3',         'group 3 - id');
-is($group3->{name},     'grp-nr-3',  'group 3 - name');
-is($group3->{priority}, 50,          'group 3 - priority');
-is($group3->{comment},  'nuff said', 'group 3 - comment');
+is($group3->{id},                         '3',         'group 3 - id');
+is($group3->{name},                       'grp-nr-3',  'group 3 - name');
+is($group3->{priority},                   50,          'group 3 - priority');
+is($group3->{comment},                    'nuff said', 'group 3 - comment');
+is($group3->{attrs}->{automnt_dir},       'a',         'group 3 - attr automnt_dir');
+is($group3->{attrs}->{automnt_src},       'b',         'group 3 - attr automnt_src');
+is($group3->{attrs}->{country},           'c',         'group 3 - attr country');
+is($group3->{attrs}->{dm_allow_shutdown}, 'd',         'group 3 - attr dm_allow_shutdown');
+is($group3->{attrs}->{hw_graphic},        'e',         'group 3 - attr hw_graphic');
+is($group3->{attrs}->{hw_monitor},        'f',         'group 3 - attr hw_monitor');
+is($group3->{attrs}->{hw_mouse},          'g',         'group 3 - attr hw_mouse');
+is($group3->{attrs}->{late_dm},           'h',         'group 3 - attr late_dm');
+is($group3->{attrs}->{netbios_workgroup}, 'i',         'group 3 - attr netbios_workgroup');
+is($group3->{attrs}->{nis_domain},        'j',         'group 3 - attr nis_domain');
+is($group3->{attrs}->{nis_servers},       'k',         'group 3 - attr nis_servers');
+is($group3->{attrs}->{sane_scanner},      'p',         'group 3 - attr sane_scanner');
+is($group3->{attrs}->{scratch},           'q',         'group 3 - attr scratch');
+is($group3->{attrs}->{slxgrp},            'r',         'group 3 - attr slxgrp');
+is($group3->{attrs}->{start_alsasound},   's',         'group 3 - attr start_alsasound');
+is($group3->{attrs}->{start_atd},         't',         'group 3 - attr start_atd');
+is($group3->{attrs}->{start_cron},        'u',         'group 3 - attr start_cron');
+is($group3->{attrs}->{start_dreshal},     'v',         'group 3 - attr start_dreshal');
+is($group3->{attrs}->{start_ntp},         'w',         'group 3 - attr start_ftp');
+is($group3->{attrs}->{start_nfsv4},       'x',         'group 3 - attr start_nfsv4');
+is($group3->{attrs}->{start_printer},     'y',         'group 3 - attr start_printer');
+is($group3->{attrs}->{start_samba},       'z',         'group 3 - attr start_samba');
+is($group3->{attrs}->{start_snmp},        'A',         'group 3 - attr start_snmp');
+is($group3->{attrs}->{start_sshd},        'B',         'group 3 - attr start_sshd');
+is($group3->{attrs}->{start_syslog},      'C',         'group 3 - attr start_syslog');
+is($group3->{attrs}->{start_x},           'D',         'group 3 - attr start_x');
+is($group3->{attrs}->{start_xdmcp},       'E',         'group 3 - attr start_xdmcp');
+is($group3->{attrs}->{tex_enable},        'F',         'group 3 - attr tex_enable');
+is($group3->{attrs}->{timezone},          'G',         'group 3 - attr timezone');
+is($group3->{attrs}->{tvout},             'H',         'group 3 - attr tvout');
+is($group3->{attrs}->{vmware},            'I',         'group 3 - attr vmware');
+is(keys %{$group3->{attrs}},              31,          'group 3 - attribute count');
 
 # fetch group 2 by a filter on id and check all values
 ok(
@@ -75,16 +148,21 @@ is($group2->{id},       2,         'group 2 - id');
 is($group2->{name},     'grp-2.0', 'group 2 - name');
 is($group2->{priority}, 30,        'group 2 - priority');
 is($group2->{comment},  undef,     'group 2 - comment');
+is(keys %{$group2->{attrs}}, 0,    'group 2 - attribute count');
 
 # fetch group 1 by filter on name and check all values
 ok(
 	my $group1 = $configDB->fetchGroupByFilter({ name => 'grp-1' }), 
 	'fetch group 1 by filter on name'
 );
-is($group1->{id},       1,       'group 1 - id');
-is($group1->{name},     'grp-1', 'group 1 - name');
-is($group1->{priority}, 50,      'group 1 - priority');
-is($group1->{comment},  '',      'group 1 - comment');
+is($group1->{id},                 1,         'group 1 - id');
+is($group1->{name},               'grp-1',   'group 1 - name');
+is($group1->{priority},           50,        'group 1 - priority');
+is($group1->{comment},            '',        'group 1 - comment');
+is(keys %{$group1->{attrs}},       3,        'group 1 - attribute count');
+is($group1->{attrs}->{slxgrp},     'slxgrp', 'group 1 - attr slxgrp');
+is($group1->{attrs}->{start_snmp}, 'no',     'group 1 - attr start_snmp');
+is($group1->{attrs}->{start_sshd}, 'yes',    'group 1 - attr start_sshd');
 
 # fetch groups 3 & 1 by id
 ok(
@@ -121,6 +199,14 @@ is(@groups1And3, 2, 'should have got 2 groups');
 is($groups1And3[0]->{id}, 1, 'first id should be 1');
 is($groups1And3[1]->{id}, 3, 'second id should be 3');
 
+# fetch group 2 by filter on comment being undef'd
+ok(
+	my @group2Only = $configDB->fetchGroupByFilter({ comment => undef }), 
+	'fetch group 2 by filter on comment being undefined'
+);
+is(@group2Only, 1, 'should have got 1 group');
+is($group2Only[0]->{id}, 2, 'first id should be 2');
+
 # try to fetch with multi-column filter
 ok(
 	($group1, $group3)
@@ -142,6 +228,83 @@ is(@groups1And3, 2, 'should have got 2 groups');
 is($groups1And3[0]->{id}, 1, 'first id should be 1');
 is($groups1And3[1]->{id}, 3, 'second id should be 3');
 
+# filter groups by different attributes & values in combination
+ok( 
+	my @group1Only = $configDB->fetchGroupByFilter( {}, undef, { 
+		start_snmp => 'no',
+	} ),
+	'fetch group 1 by filter on attribute start_snmp'
+);
+
+is(@group1Only, 1, 'should have got 1 group');
+is($group1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@group1Only = $configDB->fetchGroupByFilter( undef, 'id', { 
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	'fetch group 1 by filter on attribute start_snmp + non-existing attr'
+);
+is(@group1Only, 1, 'should have got 1 group');
+is($group1Only[0]->{id}, 1, 'first id should be 1');
+
+ok(
+	@group1Only = $configDB->fetchGroupByFilter( {
+		name     => 'grp-1',
+		priority => 50,
+	}, 'id', {
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	'fetch group 1 by multiple filter on values and attributes'
+);
+is(@group1Only, 1, 'should have got 1 group');
+is($group1Only[0]->{id}, 1, 'first id should be 1');
+
+is(
+	$configDB->fetchGroupByFilter( {
+		comment => 'xxx',
+	}, 'id', {
+		start_snmp => 'no',
+		tex_enable => undef,
+	} ),
+	undef,
+	'mismatch group 1 by filter with incorrect value'
+);
+is(
+	$configDB->fetchGroupByFilter( {
+		name => 'grp-1',
+	}, 'id', {
+		start_snmp => 'yes',
+		tex_enable => undef,
+	} ),
+	undef,
+	'mismatch group 1 by filter with incorrect attribute value'
+);
+is(
+	$configDB->fetchGroupByFilter( {
+		name => 'grp-1',
+	}, 'id', {
+		start_sshd => undef,
+	} ),
+	undef,
+	'mismatch group 1 by filter with attribute not being empty'
+);
+
+# fetch groups 1 & 2 by filter on attribute start_samba not existing
+ok(
+	my @groups1And2 = $configDB->fetchGroupByFilter( {}, undef, {
+		start_samba => undef,
+	} ), 
+	'fetch groups 1 & 2 by filter on attribute start_samba not existing'
+);
+is(@groups1And2, 2, 'should have got 2 groups');
+# now sort by ID and check if we have really got 1 and 2
+@groups1And2 = sort { $a->{id} cmp $b->{id} } @groups1And2;
+is($groups1And2[0]->{id}, 1, 'first id should be 1');
+is($groups1And2[1]->{id}, 2, 'second id should be 2');
+
 # try to fetch a couple of non-existing groups by id
 is($configDB->fetchGroupByID(-1), undef, 'group with id -1 should not exist');
 is($configDB->fetchGroupByID(0), undef, 'group with id 0 should not exist');
@@ -173,6 +336,9 @@ ok(
 is($group1->{id},   1,          'really got group number 1');
 is($group1->{name}, q{GRP-'1'}, q{really got group named "GRP-'1'"});
 
+# changing nothing at all should succeed
+ok($configDB->changeGroup(1), 'changing nothing at all in group 1');
+
 # changing a non-existing column should fail
 ok(
 	! eval { $configDB->changeGroup(1, { xname => "xx" }) }, 
diff --git a/config-db/t/15-global_info.t b/config-db/t/15-global_info.t
index 82c04997..628b2495 100644
--- a/config-db/t/15-global_info.t
+++ b/config-db/t/15-global_info.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -10,7 +13,7 @@ $configDB->connect();
 
 # fetch global-info 'next-nbd-server-port'
 ok(
-	$globalInfo = $configDB->fetchGlobalInfo('next-nbd-server-port'), 
+	my $globalInfo = $configDB->fetchGlobalInfo('next-nbd-server-port'), 
 	'fetch global-info'
 );
 is($globalInfo, '5000', 'global-info - value');
diff --git a/config-db/t/20-client_system_ref.t b/config-db/t/20-client_system_ref.t
index 646050e3..46e56ddf 100644
--- a/config-db/t/20-client_system_ref.t
+++ b/config-db/t/20-client_system_ref.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -40,7 +43,7 @@ ok(
 	'system-ID 3 has been associated to client 1'
 );
 is(
-	@systemIDs = sort($configDB->fetchSystemIDsOfClient(0)),
+	my @systemIDs = sort($configDB->fetchSystemIDsOfClient(0)),
 	0, "default client should have no system-ID"
 );
 is(
@@ -53,7 +56,7 @@ is(
 	0, "client 3 should have no system-ID"
 );
 is(
-	@clientIDs = sort($configDB->fetchClientIDsOfSystem(0)),
+	my @clientIDs = sort($configDB->fetchClientIDsOfSystem(0)),
 	0, "default system should have no client-IDs"
 );
 is(
diff --git a/config-db/t/21-group_system_ref.t b/config-db/t/21-group_system_ref.t
index e9023feb..6f92a8dd 100644
--- a/config-db/t/21-group_system_ref.t
+++ b/config-db/t/21-group_system_ref.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -39,7 +42,7 @@ ok(
 	'system-ID 3 has been associated to group 1'
 );
 is(
-	@systemIDs = sort($configDB->fetchSystemIDsOfGroup(1)),
+	my @systemIDs = sort($configDB->fetchSystemIDsOfGroup(1)),
 	1, "group 1 should have one system-ID"
 );
 is($systemIDs[0], 3, "first system of group 1 should have ID 3");
@@ -48,7 +51,7 @@ is(
 	0, "group 3 should have no system-ID"
 );
 is(
-	@groupIDs = sort($configDB->fetchGroupIDsOfSystem(0)),
+	my @groupIDs = sort($configDB->fetchGroupIDsOfSystem(0)),
 	0, "default system should have no group-IDs"
 );
 is(
diff --git a/config-db/t/22-group_client_ref.t b/config-db/t/22-group_client_ref.t
index 240fcd61..d330bc23 100644
--- a/config-db/t/22-group_client_ref.t
+++ b/config-db/t/22-group_client_ref.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -39,7 +42,7 @@ ok(
 	'client-ID 3 has been associated to group 1'
 );
 is(
-	@clientIDs = sort($configDB->fetchClientIDsOfGroup(1)),
+	my @clientIDs = sort($configDB->fetchClientIDsOfGroup(1)),
 	1, "group 1 should have one client-ID"
 );
 is($clientIDs[0], 3, "first client of group 1 should have ID 3");
@@ -48,7 +51,7 @@ is(
 	0, "group 3 should have no client-ID"
 );
 is(
-	@groupIDs = sort($configDB->fetchGroupIDsOfClient(0)),
+	my @groupIDs = sort($configDB->fetchGroupIDsOfClient(0)),
 	0, "default client should have no group-IDs"
 );
 is(
diff --git a/config-db/t/25-attributes.t b/config-db/t/25-attributes.t
index fe684679..ce83d037 100644
--- a/config-db/t/25-attributes.t
+++ b/config-db/t/25-attributes.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init
@@ -9,114 +12,114 @@ my $configDB = OpenSLX::ConfigDB->new;
 $configDB->connect();
 
 my $defaultAttrs = {	# mostly copied from DBSchema
-	'attr_ramfs_fsmods' => '',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => 'forcedeth e1000 e100 tg3 via-rhine r8169 pcnet32',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => 'de',
-	'attr_dm_allow_shutdown' => 'user',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => 'no',
-	'attr_netbios_workgroup' => 'slx-network',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => 'yes',
-	'attr_start_atd' => 'no',
-	'attr_start_cron' => 'no',
-	'attr_start_dreshal' => 'yes',
-	'attr_start_ntp' => 'initial',
-	'attr_start_nfsv4' => 'no',
-	'attr_start_printer' => 'no',
-	'attr_start_samba' => 'may',
-	'attr_start_snmp' => 'no',
-	'attr_start_sshd' => 'yes',
-	'attr_start_syslog' => 'yes',
-	'attr_start_x' => 'yes',
-	'attr_start_xdmcp' => 'kdm',
-	'attr_tex_enable' => 'no',
-	'attr_timezone' => 'Europe/Berlin',
-	'attr_tvout' => 'no',
-	'attr_vmware' => 'no',
+	'ramfs_fsmods' => '',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => 'forcedeth e1000 e100 tg3 via-rhine r8169 pcnet32',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => 'de',
+	'dm_allow_shutdown' => 'user',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => 'no',
+	'netbios_workgroup' => 'slx-network',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '',
+	'slxgrp' => '',
+	'start_alsasound' => 'yes',
+	'start_atd' => 'no',
+	'start_cron' => 'no',
+	'start_dreshal' => 'yes',
+	'start_ntp' => 'initial',
+	'start_nfsv4' => 'no',
+	'start_printer' => 'no',
+	'start_samba' => 'may',
+	'start_snmp' => 'no',
+	'start_sshd' => 'yes',
+	'start_syslog' => 'yes',
+	'start_x' => 'yes',
+	'start_xdmcp' => 'kdm',
+	'tex_enable' => 'no',
+	'timezone' => 'Europe/Berlin',
+	'tvout' => 'no',
+	'vmware' => 'no',
 };
 ok(
-	$configDB->changeSystem(0, $defaultAttrs),
+	$configDB->changeSystem(0, { attrs => $defaultAttrs } ),
 	'attributes of default system have been set'
 );
 my $defaultSystem = $configDB->fetchSystemByID(0);
 
 my $system1 = $configDB->fetchSystemByID(1);
 my $sys1Attrs = {
-	'attr_ramfs_fsmods' => 'squashfs',
-	'attr_ramfs_nicmods' => 'forcedeth e1000 r8169',
-	'attr_start_x' => 'no',
-	'attr_start_xdmcp' => '',
+	'ramfs_fsmods' => 'squashfs',
+	'ramfs_nicmods' => 'forcedeth e1000 r8169',
+	'start_x' => 'no',
+	'start_xdmcp' => '',
 };
 ok(
-	$configDB->changeSystem(1, $sys1Attrs),
+	$configDB->changeSystem(1, { attrs => $sys1Attrs } ),
 	'attributes of system 1 have been set'
 );
 
 my $system3 = $configDB->fetchSystemByID(3);
 my $sys3Attrs = {
-	'attr_ramfs_fsmods' => '-4',
-	'attr_ramfs_miscmods' => '-3',
-	'attr_ramfs_nicmods' => '-2',
-	'attr_ramfs_screen' => '-1',
-
-	'attr_automnt_dir' => '1',
-	'attr_automnt_src' => '2',
-	'attr_country' => '3',
-	'attr_dm_allow_shutdown' => '4',
-	'attr_hw_graphic' => '5',
-	'attr_hw_monitor' => '6',
-	'attr_hw_mouse' => '7',
-	'attr_late_dm' => '8',
-	'attr_netbios_workgroup' => '9',
-	'attr_nis_domain' => '10',
-	'attr_nis_servers' => '11',
-	'attr_sane_scanner' => '12',
-	'attr_scratch' => '13',
-	'attr_slxgrp' => '14',
-	'attr_start_alsasound' => '15',
-	'attr_start_atd' => '16',
-	'attr_start_cron' => '17',
-	'attr_start_dreshal' => '18',
-	'attr_start_ntp' => '19',
-	'attr_start_nfsv4' => '20',
-	'attr_start_printer' => '21',
-	'attr_start_samba' => '22',
-	'attr_start_snmp' => '23',
-	'attr_start_sshd' => '24',
-	'attr_start_syslog' => '25',
-	'attr_start_x' => '26',
-	'attr_start_xdmcp' => '27',
-	'attr_tex_enable' => '28',
-	'attr_timezone' => '29',
-	'attr_tvout' => '30',
-	'attr_vmware' => '31',
+	'ramfs_fsmods' => '-4',
+	'ramfs_miscmods' => '-3',
+	'ramfs_nicmods' => '-2',
+	'ramfs_screen' => '-1',
+
+	'automnt_dir' => '1',
+	'automnt_src' => '2',
+	'country' => '3',
+	'dm_allow_shutdown' => '4',
+	'hw_graphic' => '5',
+	'hw_monitor' => '6',
+	'hw_mouse' => '7',
+	'late_dm' => '8',
+	'netbios_workgroup' => '9',
+	'nis_domain' => '10',
+	'nis_servers' => '11',
+	'sane_scanner' => '12',
+	'scratch' => '13',
+	'slxgrp' => '14',
+	'start_alsasound' => '15',
+	'start_atd' => '16',
+	'start_cron' => '17',
+	'start_dreshal' => '18',
+	'start_ntp' => '19',
+	'start_nfsv4' => '20',
+	'start_printer' => '21',
+	'start_samba' => '22',
+	'start_snmp' => '23',
+	'start_sshd' => '24',
+	'start_syslog' => '25',
+	'start_x' => '26',
+	'start_xdmcp' => '27',
+	'tex_enable' => '28',
+	'timezone' => '29',
+	'tvout' => '30',
+	'vmware' => '31',
 };
 ok(
-	$configDB->changeSystem(3, $sys3Attrs),
+	$configDB->changeSystem(3, { attrs => $sys3Attrs } ),
 	'attributes of system 3 have been set'
 );
 
 my $defaultClient = $configDB->fetchClientByID(0);
 my $defaultClientAttrs = {
 	# pretend the whole computer centre has been warped to London ;-)
-	'attr_timezone' => 'Europe/London',
+	'timezone' => 'Europe/London',
 	# pretend we wanted to activate snmp globally (e.g. for testing)
-	'attr_start_snmp' => 'yes',
+	'start_snmp' => 'yes',
 };
 ok(
-	$configDB->changeClient(0, $defaultClientAttrs),
+	$configDB->changeClient(0, { attrs => $defaultClientAttrs } ),
 	'attributes of default client have been set'
 );
 
@@ -124,42 +127,42 @@ ok(
 # default system attributes overruled by system attributes overruled by
 # default client attributes:
 my $shouldBeAttrs1 = {
-	'attr_ramfs_fsmods' => 'squashfs',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => 'forcedeth e1000 r8169',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => 'de',
-	'attr_dm_allow_shutdown' => 'user',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => 'no',
-	'attr_netbios_workgroup' => 'slx-network',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => 'yes',
-	'attr_start_atd' => 'no',
-	'attr_start_cron' => 'no',
-	'attr_start_dreshal' => 'yes',
-	'attr_start_ntp' => 'initial',
-	'attr_start_nfsv4' => 'no',
-	'attr_start_printer' => 'no',
-	'attr_start_samba' => 'may',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => 'yes',
-	'attr_start_syslog' => 'yes',
-	'attr_start_x' => 'no',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => 'no',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => 'no',
-	'attr_vmware' => 'no',
+	'ramfs_fsmods' => 'squashfs',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => 'forcedeth e1000 r8169',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => 'de',
+	'dm_allow_shutdown' => 'user',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => 'no',
+	'netbios_workgroup' => 'slx-network',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '',
+	'slxgrp' => '',
+	'start_alsasound' => 'yes',
+	'start_atd' => 'no',
+	'start_cron' => 'no',
+	'start_dreshal' => 'yes',
+	'start_ntp' => 'initial',
+	'start_nfsv4' => 'no',
+	'start_printer' => 'no',
+	'start_samba' => 'may',
+	'start_snmp' => 'yes',
+	'start_sshd' => 'yes',
+	'start_syslog' => 'yes',
+	'start_x' => 'no',
+	'start_xdmcp' => '',
+	'tex_enable' => 'no',
+	'timezone' => 'Europe/London',
+	'tvout' => 'no',
+	'vmware' => 'no',
 };
 my $mergedSystem1 = $configDB->fetchSystemByID(1);
 ok(
@@ -168,49 +171,49 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs1) {
 	is(
-		$mergedSystem1->{$key} || '', $shouldBeAttrs1->{$key} || '', 
+		$mergedSystem1->{attrs}->{$key}, $shouldBeAttrs1->{$key}, 
 		"checking merged attribute $key for system 1"
 	);
 }
 
 # check merging code for completeness (using all attributes):
 my $shouldBeAttrs3 = {
-	'attr_ramfs_fsmods' => '-4',
-	'attr_ramfs_miscmods' => '-3',
-	'attr_ramfs_nicmods' => '-2',
-	'attr_ramfs_screen' => '-1',
-
-	'attr_automnt_dir' => '1',
-	'attr_automnt_src' => '2',
-	'attr_country' => '3',
-	'attr_dm_allow_shutdown' => '4',
-	'attr_hw_graphic' => '5',
-	'attr_hw_monitor' => '6',
-	'attr_hw_mouse' => '7',
-	'attr_late_dm' => '8',
-	'attr_netbios_workgroup' => '9',
-	'attr_nis_domain' => '10',
-	'attr_nis_servers' => '11',
-	'attr_sane_scanner' => '12',
-	'attr_scratch' => '13',
-	'attr_slxgrp' => '14',
-	'attr_start_alsasound' => '15',
-	'attr_start_atd' => '16',
-	'attr_start_cron' => '17',
-	'attr_start_dreshal' => '18',
-	'attr_start_ntp' => '19',
-	'attr_start_nfsv4' => '20',
-	'attr_start_printer' => '21',
-	'attr_start_samba' => '22',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '24',
-	'attr_start_syslog' => '25',
-	'attr_start_x' => '26',
-	'attr_start_xdmcp' => '27',
-	'attr_tex_enable' => '28',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => '30',
-	'attr_vmware' => '31',
+	'ramfs_fsmods' => '-4',
+	'ramfs_miscmods' => '-3',
+	'ramfs_nicmods' => '-2',
+	'ramfs_screen' => '-1',
+
+	'automnt_dir' => '1',
+	'automnt_src' => '2',
+	'country' => '3',
+	'dm_allow_shutdown' => '4',
+	'hw_graphic' => '5',
+	'hw_monitor' => '6',
+	'hw_mouse' => '7',
+	'late_dm' => '8',
+	'netbios_workgroup' => '9',
+	'nis_domain' => '10',
+	'nis_servers' => '11',
+	'sane_scanner' => '12',
+	'scratch' => '13',
+	'slxgrp' => '14',
+	'start_alsasound' => '15',
+	'start_atd' => '16',
+	'start_cron' => '17',
+	'start_dreshal' => '18',
+	'start_ntp' => '19',
+	'start_nfsv4' => '20',
+	'start_printer' => '21',
+	'start_samba' => '22',
+	'start_snmp' => 'yes',
+	'start_sshd' => '24',
+	'start_syslog' => '25',
+	'start_x' => '26',
+	'start_xdmcp' => '27',
+	'tex_enable' => '28',
+	'timezone' => 'Europe/London',
+	'tvout' => '30',
+	'vmware' => '31',
 };
 my $mergedSystem3 = $configDB->fetchSystemByID(3);
 ok(
@@ -219,7 +222,7 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs3) {
 	is(
-		$mergedSystem3->{$key}, $shouldBeAttrs3->{$key}, 
+		$mergedSystem3->{attrs}->{$key}, $shouldBeAttrs3->{$key}, 
 		"checking merged attribute $key for system 3"
 	);
 }
@@ -229,34 +232,34 @@ my $group1 = $configDB->fetchGroupByID(1);
 my $group1Attrs = {
 	'priority' => '50',
 	# this group of clients is connected via underwater cable ...
-	'attr_timezone' => 'America/New_York',
+	'timezone' => 'America/New_York',
 	# ... and use a local scratch partition
-	'attr_scratch' => '/dev/sdd1',
+	'scratch' => '/dev/sdd1',
 	# the following should be a noop (as that attribute is system-specific)
-#	'attr_ramfs_nicmods' => 'e1000',
+#	'ramfs_nicmods' => 'e1000',
 };
 ok(
-	$configDB->changeGroup(1, $group1Attrs),
+	$configDB->changeGroup(1, { attrs => $group1Attrs } ),
 	'attributes of group 1 have been set'
 );
 my $group3 = $configDB->fetchGroupByID(3);
 my $group3Attrs = {
 	'priority' => '30',
 	# this specific client group is older and thus has a different scratch
-	'attr_scratch' => '/dev/hdd1',
-	'attr_vmware' => 'yes',
+	'scratch' => '/dev/hdd1',
+	'vmware' => 'yes',
 };
 ok(
-	$configDB->changeGroup(3, $group3Attrs),
+	$configDB->changeGroup(3, { attrs => $group3Attrs } ),
 	'attributes of group 3 have been set'
 );
 my $client1 = $configDB->fetchClientByID(1);
 my $client1Attrs = {
 	# this specific client uses yet another local scratch partition
-	'attr_scratch' => '/dev/sdx3',
+	'scratch' => '/dev/sdx3',
 };
 ok(
-	$configDB->changeClient(1, $client1Attrs),
+	$configDB->changeClient(1, { attrs => $client1Attrs } ),
 	'attributes of client 1 have been set'
 );
 ok(
@@ -272,42 +275,42 @@ ok(
 # default client attributes overruled by group attributes (ordererd by priority) 
 # overruled by specific client attributes:
 $shouldBeAttrs1 = {
-	'attr_ramfs_fsmods' => '',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => '',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => '',
-	'attr_dm_allow_shutdown' => '',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => '',
-	'attr_netbios_workgroup' => '',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '/dev/sdx3',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => '',
-	'attr_start_atd' => '',
-	'attr_start_cron' => '',
-	'attr_start_dreshal' => '',
-	'attr_start_ntp' => '',
-	'attr_start_nfsv4' => '',
-	'attr_start_printer' => '',
-	'attr_start_samba' => '',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '',
-	'attr_start_syslog' => '',
-	'attr_start_x' => '',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => '',
-	'attr_timezone' => 'America/New_York',
-	'attr_tvout' => '',
-	'attr_vmware' => '',
+	'ramfs_fsmods' => '',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => '',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => '',
+	'dm_allow_shutdown' => '',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => '',
+	'netbios_workgroup' => '',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '/dev/sdx3',
+	'slxgrp' => '',
+	'start_alsasound' => '',
+	'start_atd' => '',
+	'start_cron' => '',
+	'start_dreshal' => '',
+	'start_ntp' => '',
+	'start_nfsv4' => '',
+	'start_printer' => '',
+	'start_samba' => '',
+	'start_snmp' => 'yes',
+	'start_sshd' => '',
+	'start_syslog' => '',
+	'start_x' => '',
+	'start_xdmcp' => '',
+	'tex_enable' => '',
+	'timezone' => 'America/New_York',
+	'tvout' => '',
+	'vmware' => '',
 };
 my $mergedClient1 = $configDB->fetchClientByID(1);
 ok(
@@ -316,49 +319,53 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs1) {
 	is(
-		$mergedClient1->{$key} || '', $shouldBeAttrs1->{$key} || '', 
+		$mergedClient1->{attrs}->{$key} || '', $shouldBeAttrs1->{$key} || '', 
 		"checking merged attribute $key for client 1"
 	);
 }
 
 $shouldBeAttrs3 = {
-	'attr_ramfs_fsmods' => '',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => '',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => '',
-	'attr_dm_allow_shutdown' => '',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => '',
-	'attr_netbios_workgroup' => '',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => '',
-	'attr_start_atd' => '',
-	'attr_start_cron' => '',
-	'attr_start_dreshal' => '',
-	'attr_start_ntp' => '',
-	'attr_start_nfsv4' => '',
-	'attr_start_printer' => '',
-	'attr_start_samba' => '',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '',
-	'attr_start_syslog' => '',
-	'attr_start_x' => '',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => '',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => '',
-	'attr_vmware' => '',
+	'ramfs_fsmods' => '',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => '',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => '',
+	'dm_allow_shutdown' => '',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => '',
+	'netbios_workgroup' => '',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '',
+	'slxgrp' => '',
+	'start_alsasound' => '',
+	'start_atd' => '',
+	'start_cron' => '',
+	'start_dreshal' => '',
+	'start_ntp' => '',
+	'start_nfsv4' => '',
+	'start_printer' => '',
+	'start_samba' => '',
+	'start_snmp' => 'yes',
+	'start_sshd' => '',
+	'start_syslog' => '',
+	'start_x' => '',
+	'start_xdmcp' => '',
+	'tex_enable' => '',
+	'timezone' => 'Europe/London',
+	'tvout' => '',
+	'vmware' => '',
 };
+
+# remove all attributes from client 3
+$configDB->changeClient(3, { attrs => {} } );
+
 my $mergedClient3 = $configDB->fetchClientByID(3);
 ok(
 	$configDB->mergeDefaultAndGroupAttributesIntoClient($mergedClient3),
@@ -366,7 +373,7 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs1) {
 	is(
-		$mergedClient3->{$key} || '', $shouldBeAttrs3->{$key} || '', 
+		$mergedClient3->{attrs}->{$key} || '', $shouldBeAttrs3->{$key} || '', 
 		"checking merged attribute $key for client 3"
 	);
 }
@@ -377,42 +384,42 @@ ok(
 	'group-IDs of default client have been set'
 );
 $shouldBeAttrs1 = {
-	'attr_ramfs_fsmods' => '',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => '',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => '',
-	'attr_dm_allow_shutdown' => '',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => '',
-	'attr_netbios_workgroup' => '',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '/dev/sdx3',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => '',
-	'attr_start_atd' => '',
-	'attr_start_cron' => '',
-	'attr_start_dreshal' => '',
-	'attr_start_ntp' => '',
-	'attr_start_nfsv4' => '',
-	'attr_start_printer' => '',
-	'attr_start_samba' => '',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '',
-	'attr_start_syslog' => '',
-	'attr_start_x' => '',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => '',
-	'attr_timezone' => 'America/New_York',
-	'attr_tvout' => '',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => '',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => '',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => '',
+	'dm_allow_shutdown' => '',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => '',
+	'netbios_workgroup' => '',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '/dev/sdx3',
+	'slxgrp' => '',
+	'start_alsasound' => '',
+	'start_atd' => '',
+	'start_cron' => '',
+	'start_dreshal' => '',
+	'start_ntp' => '',
+	'start_nfsv4' => '',
+	'start_printer' => '',
+	'start_samba' => '',
+	'start_snmp' => 'yes',
+	'start_sshd' => '',
+	'start_syslog' => '',
+	'start_x' => '',
+	'start_xdmcp' => '',
+	'tex_enable' => '',
+	'timezone' => 'America/New_York',
+	'tvout' => '',
+	'vmware' => 'yes',
 };
 $mergedClient1 = $configDB->fetchClientByID(1);
 ok(
@@ -421,48 +428,48 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs1) {
 	is(
-		$mergedClient1->{$key} || '', $shouldBeAttrs1->{$key} || '', 
+		$mergedClient1->{attrs}->{$key} || '', $shouldBeAttrs1->{$key} || '', 
 		"checking merged attribute $key for client 1"
 	);
 }
 
 $shouldBeAttrs3 = {
-	'attr_ramfs_fsmods' => '',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => '',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => '',
-	'attr_dm_allow_shutdown' => '',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => '',
-	'attr_netbios_workgroup' => '',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '/dev/hdd1',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => '',
-	'attr_start_atd' => '',
-	'attr_start_cron' => '',
-	'attr_start_dreshal' => '',
-	'attr_start_ntp' => '',
-	'attr_start_nfsv4' => '',
-	'attr_start_printer' => '',
-	'attr_start_samba' => '',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '',
-	'attr_start_syslog' => '',
-	'attr_start_x' => '',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => '',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => '',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => '',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => '',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => '',
+	'dm_allow_shutdown' => '',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => '',
+	'netbios_workgroup' => '',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '/dev/hdd1',
+	'slxgrp' => '',
+	'start_alsasound' => '',
+	'start_atd' => '',
+	'start_cron' => '',
+	'start_dreshal' => '',
+	'start_ntp' => '',
+	'start_nfsv4' => '',
+	'start_printer' => '',
+	'start_samba' => '',
+	'start_snmp' => 'yes',
+	'start_sshd' => '',
+	'start_syslog' => '',
+	'start_x' => '',
+	'start_xdmcp' => '',
+	'tex_enable' => '',
+	'timezone' => 'Europe/London',
+	'tvout' => '',
+	'vmware' => 'yes',
 };
 $mergedClient3 = $configDB->fetchClientByID(3);
 ok(
@@ -471,7 +478,7 @@ ok(
 );
 foreach my $key (sort keys %$shouldBeAttrs1) {
 	is(
-		$mergedClient3->{$key} || '', $shouldBeAttrs3->{$key} || '', 
+		$mergedClient3->{attrs}->{$key} || '', $shouldBeAttrs3->{$key} || '', 
 		"checking merged attribute $key for client 3"
 	);
 }
@@ -483,46 +490,46 @@ ok(
 	'merging system 1 into client 1'
 );
 my $shouldBeAttrs11 = {
-	'attr_ramfs_fsmods' => 'squashfs',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => 'forcedeth e1000 r8169',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => 'de',
-	'attr_dm_allow_shutdown' => 'user',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => 'no',
-	'attr_netbios_workgroup' => 'slx-network',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '/dev/sdx3',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => 'yes',
-	'attr_start_atd' => 'no',
-	'attr_start_cron' => 'no',
-	'attr_start_dreshal' => 'yes',
-	'attr_start_ntp' => 'initial',
-	'attr_start_nfsv4' => 'no',
-	'attr_start_printer' => 'no',
-	'attr_start_samba' => 'may',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => 'yes',
-	'attr_start_syslog' => 'yes',
-	'attr_start_x' => 'no',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => 'no',
-	'attr_timezone' => 'America/New_York',
-	'attr_tvout' => 'no',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => 'squashfs',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => 'forcedeth e1000 r8169',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => 'de',
+	'dm_allow_shutdown' => 'user',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => 'no',
+	'netbios_workgroup' => 'slx-network',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '/dev/sdx3',
+	'slxgrp' => '',
+	'start_alsasound' => 'yes',
+	'start_atd' => 'no',
+	'start_cron' => 'no',
+	'start_dreshal' => 'yes',
+	'start_ntp' => 'initial',
+	'start_nfsv4' => 'no',
+	'start_printer' => 'no',
+	'start_samba' => 'may',
+	'start_snmp' => 'yes',
+	'start_sshd' => 'yes',
+	'start_syslog' => 'yes',
+	'start_x' => 'no',
+	'start_xdmcp' => '',
+	'tex_enable' => 'no',
+	'timezone' => 'America/New_York',
+	'tvout' => 'no',
+	'vmware' => 'yes',
 };
 foreach my $key (sort keys %$shouldBeAttrs11) {
 	is(
-		$fullMerge11->{$key} || '', $shouldBeAttrs11->{$key} || '', 
+		$fullMerge11->{attrs}->{$key} || '', $shouldBeAttrs11->{$key} || '', 
 		"checking merged attribute $key for client 1 / system 1"
 	);
 }
@@ -533,46 +540,46 @@ ok(
 	'merging system 1 into client 3'
 );
 my $shouldBeAttrs31 = {
-	'attr_ramfs_fsmods' => 'squashfs',
-	'attr_ramfs_miscmods' => '',
-	'attr_ramfs_nicmods' => 'forcedeth e1000 r8169',
-	'attr_ramfs_screen' => '',
-
-	'attr_automnt_dir' => '',
-	'attr_automnt_src' => '',
-	'attr_country' => 'de',
-	'attr_dm_allow_shutdown' => 'user',
-	'attr_hw_graphic' => '',
-	'attr_hw_monitor' => '',
-	'attr_hw_mouse' => '',
-	'attr_late_dm' => 'no',
-	'attr_netbios_workgroup' => 'slx-network',
-	'attr_nis_domain' => '',
-	'attr_nis_servers' => '',
-	'attr_sane_scanner' => '',
-	'attr_scratch' => '/dev/hdd1',
-	'attr_slxgrp' => '',
-	'attr_start_alsasound' => 'yes',
-	'attr_start_atd' => 'no',
-	'attr_start_cron' => 'no',
-	'attr_start_dreshal' => 'yes',
-	'attr_start_ntp' => 'initial',
-	'attr_start_nfsv4' => 'no',
-	'attr_start_printer' => 'no',
-	'attr_start_samba' => 'may',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => 'yes',
-	'attr_start_syslog' => 'yes',
-	'attr_start_x' => 'no',
-	'attr_start_xdmcp' => '',
-	'attr_tex_enable' => 'no',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => 'no',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => 'squashfs',
+	'ramfs_miscmods' => '',
+	'ramfs_nicmods' => 'forcedeth e1000 r8169',
+	'ramfs_screen' => '',
+
+	'automnt_dir' => '',
+	'automnt_src' => '',
+	'country' => 'de',
+	'dm_allow_shutdown' => 'user',
+	'hw_graphic' => '',
+	'hw_monitor' => '',
+	'hw_mouse' => '',
+	'late_dm' => 'no',
+	'netbios_workgroup' => 'slx-network',
+	'nis_domain' => '',
+	'nis_servers' => '',
+	'sane_scanner' => '',
+	'scratch' => '/dev/hdd1',
+	'slxgrp' => '',
+	'start_alsasound' => 'yes',
+	'start_atd' => 'no',
+	'start_cron' => 'no',
+	'start_dreshal' => 'yes',
+	'start_ntp' => 'initial',
+	'start_nfsv4' => 'no',
+	'start_printer' => 'no',
+	'start_samba' => 'may',
+	'start_snmp' => 'yes',
+	'start_sshd' => 'yes',
+	'start_syslog' => 'yes',
+	'start_x' => 'no',
+	'start_xdmcp' => '',
+	'tex_enable' => 'no',
+	'timezone' => 'Europe/London',
+	'tvout' => 'no',
+	'vmware' => 'yes',
 };
 foreach my $key (sort keys %$shouldBeAttrs31) {
 	is(
-		$fullMerge31->{$key} || '', $shouldBeAttrs31->{$key} || '', 
+		$fullMerge31->{attrs}->{$key} || '', $shouldBeAttrs31->{$key} || '', 
 		"checking merged attribute $key for client 3 / system 1"
 	);
 }
@@ -583,46 +590,46 @@ ok(
 	'merging system 3 into client 1'
 );
 my $shouldBeAttrs13 = {
-	'attr_ramfs_fsmods' => '-4',
-	'attr_ramfs_miscmods' => '-3',
-	'attr_ramfs_nicmods' => '-2',
-	'attr_ramfs_screen' => '-1',
-
-	'attr_automnt_dir' => '1',
-	'attr_automnt_src' => '2',
-	'attr_country' => '3',
-	'attr_dm_allow_shutdown' => '4',
-	'attr_hw_graphic' => '5',
-	'attr_hw_monitor' => '6',
-	'attr_hw_mouse' => '7',
-	'attr_late_dm' => '8',
-	'attr_netbios_workgroup' => '9',
-	'attr_nis_domain' => '10',
-	'attr_nis_servers' => '11',
-	'attr_sane_scanner' => '12',
-	'attr_scratch' => '/dev/sdx3',
-	'attr_slxgrp' => '14',
-	'attr_start_alsasound' => '15',
-	'attr_start_atd' => '16',
-	'attr_start_cron' => '17',
-	'attr_start_dreshal' => '18',
-	'attr_start_ntp' => '19',
-	'attr_start_nfsv4' => '20',
-	'attr_start_printer' => '21',
-	'attr_start_samba' => '22',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '24',
-	'attr_start_syslog' => '25',
-	'attr_start_x' => '26',
-	'attr_start_xdmcp' => '27',
-	'attr_tex_enable' => '28',
-	'attr_timezone' => 'America/New_York',
-	'attr_tvout' => '30',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => '-4',
+	'ramfs_miscmods' => '-3',
+	'ramfs_nicmods' => '-2',
+	'ramfs_screen' => '-1',
+
+	'automnt_dir' => '1',
+	'automnt_src' => '2',
+	'country' => '3',
+	'dm_allow_shutdown' => '4',
+	'hw_graphic' => '5',
+	'hw_monitor' => '6',
+	'hw_mouse' => '7',
+	'late_dm' => '8',
+	'netbios_workgroup' => '9',
+	'nis_domain' => '10',
+	'nis_servers' => '11',
+	'sane_scanner' => '12',
+	'scratch' => '/dev/sdx3',
+	'slxgrp' => '14',
+	'start_alsasound' => '15',
+	'start_atd' => '16',
+	'start_cron' => '17',
+	'start_dreshal' => '18',
+	'start_ntp' => '19',
+	'start_nfsv4' => '20',
+	'start_printer' => '21',
+	'start_samba' => '22',
+	'start_snmp' => 'yes',
+	'start_sshd' => '24',
+	'start_syslog' => '25',
+	'start_x' => '26',
+	'start_xdmcp' => '27',
+	'tex_enable' => '28',
+	'timezone' => 'America/New_York',
+	'tvout' => '30',
+	'vmware' => 'yes',
 };
 foreach my $key (sort keys %$shouldBeAttrs13) {
 	is(
-		$fullMerge13->{$key} || '', $shouldBeAttrs13->{$key} || '', 
+		$fullMerge13->{attrs}->{$key} || '', $shouldBeAttrs13->{$key} || '', 
 		"checking merged attribute $key for client 1 / system 3"
 	);
 }
@@ -633,46 +640,46 @@ ok(
 	'merging system 3 into client 3'
 );
 my $shouldBeAttrs33 = {
-	'attr_ramfs_fsmods' => '-4',
-	'attr_ramfs_miscmods' => '-3',
-	'attr_ramfs_nicmods' => '-2',
-	'attr_ramfs_screen' => '-1',
-
-	'attr_automnt_dir' => '1',
-	'attr_automnt_src' => '2',
-	'attr_country' => '3',
-	'attr_dm_allow_shutdown' => '4',
-	'attr_hw_graphic' => '5',
-	'attr_hw_monitor' => '6',
-	'attr_hw_mouse' => '7',
-	'attr_late_dm' => '8',
-	'attr_netbios_workgroup' => '9',
-	'attr_nis_domain' => '10',
-	'attr_nis_servers' => '11',
-	'attr_sane_scanner' => '12',
-	'attr_scratch' => '/dev/hdd1',
-	'attr_slxgrp' => '14',
-	'attr_start_alsasound' => '15',
-	'attr_start_atd' => '16',
-	'attr_start_cron' => '17',
-	'attr_start_dreshal' => '18',
-	'attr_start_ntp' => '19',
-	'attr_start_nfsv4' => '20',
-	'attr_start_printer' => '21',
-	'attr_start_samba' => '22',
-	'attr_start_snmp' => 'yes',
-	'attr_start_sshd' => '24',
-	'attr_start_syslog' => '25',
-	'attr_start_x' => '26',
-	'attr_start_xdmcp' => '27',
-	'attr_tex_enable' => '28',
-	'attr_timezone' => 'Europe/London',
-	'attr_tvout' => '30',
-	'attr_vmware' => 'yes',
+	'ramfs_fsmods' => '-4',
+	'ramfs_miscmods' => '-3',
+	'ramfs_nicmods' => '-2',
+	'ramfs_screen' => '-1',
+
+	'automnt_dir' => '1',
+	'automnt_src' => '2',
+	'country' => '3',
+	'dm_allow_shutdown' => '4',
+	'hw_graphic' => '5',
+	'hw_monitor' => '6',
+	'hw_mouse' => '7',
+	'late_dm' => '8',
+	'netbios_workgroup' => '9',
+	'nis_domain' => '10',
+	'nis_servers' => '11',
+	'sane_scanner' => '12',
+	'scratch' => '/dev/hdd1',
+	'slxgrp' => '14',
+	'start_alsasound' => '15',
+	'start_atd' => '16',
+	'start_cron' => '17',
+	'start_dreshal' => '18',
+	'start_ntp' => '19',
+	'start_nfsv4' => '20',
+	'start_printer' => '21',
+	'start_samba' => '22',
+	'start_snmp' => 'yes',
+	'start_sshd' => '24',
+	'start_syslog' => '25',
+	'start_x' => '26',
+	'start_xdmcp' => '27',
+	'tex_enable' => '28',
+	'timezone' => 'Europe/London',
+	'tvout' => '30',
+	'vmware' => 'yes',
 };
 foreach my $key (sort keys %$shouldBeAttrs33) {
 	is(
-		$fullMerge33->{$key} || '', $shouldBeAttrs33->{$key} || '', 
+		$fullMerge33->{attrs}->{$key} || '', $shouldBeAttrs33->{$key} || '', 
 		"checking merged attribute $key for client 3 / system 3"
 	);
 }
diff --git a/config-db/t/29-transaction.t b/config-db/t/29-transaction.t
index 89b0df83..2088a16c 100644
--- a/config-db/t/29-transaction.t
+++ b/config-db/t/29-transaction.t
@@ -1,5 +1,8 @@
 use Test::More qw(no_plan);
 
+use strict;
+use warnings;
+
 use lib '/opt/openslx/lib';
 
 # basic init