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

12 files changed, 1042 insertions, 507 deletions

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