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Diffstat (limited to 'sys-utils/mount.8')
| -rw-r--r-- | sys-utils/mount.8 | 350 |
1 files changed, 2 insertions, 348 deletions
diff --git a/sys-utils/mount.8 b/sys-utils/mount.8 index 25c9b4cdb..52c8bdab3 100644 --- a/sys-utils/mount.8 +++ b/sys-utils/mount.8 @@ -1550,354 +1550,8 @@ starting with 2.6.29. Further, this option is valid only if CONFIG_DEVPTS_MULTIPLE_INSTANCES is enabled in the kernel configuration. -.SS "Mount options for ext2" -The `ext2' filesystem is the standard Linux filesystem. -For most mount options the default -is determined by the filesystem superblock. Set them with -.BR tune2fs (8). -.TP -.BR acl | noacl -Support POSIX Access Control Lists (or not). -.\" requires CONFIG_EXT2_FS_POSIX_ACL -.TP -.BR bsddf | minixdf -Set the behavior for the -.I statfs -system call. The -.B minixdf -behavior is to return in the -.I f_blocks -field the total number of blocks of the filesystem, while the -.B bsddf -behavior (which is the default) is to subtract the overhead blocks -used by the ext2 filesystem and not available for file storage. Thus -.sp 1 -% mount /k \-o minixdf; df /k; umount /k -.TS -tab(#); -l2 l2 r2 l2 l2 l -l c r c c l. -Filesystem#1024-blocks#Used#Available#Capacity#Mounted on -/dev/sda6#2630655#86954#2412169#3%#/k -.TE -.sp 1 -% mount /k \-o bsddf; df /k; umount /k -.TS -tab(#); -l2 l2 r2 l2 l2 l -l c r c c l. -Filesystem#1024-blocks#Used#Available#Capacity#Mounted on -/dev/sda6#2543714#13#2412169#0%#/k -.TE -.sp 1 -(Note that this example shows that one can add command-line options -to the options given in -.IR /etc/fstab .) - -.TP -.BR check=none " or " nocheck -No checking is done at mount time. This is the default. This is fast. -It is wise to invoke -.BR e2fsck (8) -every now and then, e.g.\& at boot time. The non-default behavior is unsupported -(check=normal and check=strict options have been removed). Note that these mount options -don't have to be supported if ext4 kernel driver is used for ext2 and ext3 filesystems. -.TP -.B debug -Print debugging info upon each (re)mount. -.TP -.BR errors= { continue | remount-ro | panic } -Define the behavior when an error is encountered. -(Either ignore errors and just mark the filesystem erroneous and continue, -or remount the filesystem read-only, or panic and halt the system.) -The default is set in the filesystem superblock, and can be -changed using -.BR tune2fs (8). -.TP -.BR grpid | bsdgroups " and " nogrpid | sysvgroups -These options define what group ID a newly created file gets. -When -.B grpid -is set, it takes the group ID of the directory in which it is created; -otherwise (the default) it takes the fsgid of the current process, unless -the directory has the set-group-ID bit set, in which case it takes the GID -from the parent directory, and also gets the set-group-ID bit set -if it is a directory itself. -.TP -.BR grpquota | noquota | quota | usrquota -The usrquota (same as quota) mount option enables user quota support on the -filesystem. grpquota enables group quotas support. You need the quota utilities -to actually enable and manage the quota system. -.TP -.B nouid32 -Disables 32-bit UIDs and GIDs. This is for interoperability with older -kernels which only store and expect 16-bit values. -.TP -.BR oldalloc " or " orlov -Use old allocator or Orlov allocator for new inodes. Orlov is default. -.TP -\fBresgid=\fP\,\fIn\fP and \fBresuid=\fP\,\fIn\fP -The ext2 filesystem reserves a certain percentage of the available -space (by default 5%, see -.BR mke2fs (8) -and -.BR tune2fs (8)). -These options determine who can use the reserved blocks. -(Roughly: whoever has the specified UID, or belongs to the specified group.) -.TP -.BI sb= n -Instead of block 1, use block -.I n -as superblock. This could be useful when the filesystem has been damaged. -See -.B dumpe2fs /dev/foo | grep superblock -to list alternatively usable superblocks. -.TP -.BR user_xattr | nouser_xattr -Support "user." extended attributes (or not). -.\" requires CONFIG_EXT2_FS_XATTR - -.SS "Mount options for ext3" -The ext3 filesystem is a version of the ext2 filesystem which has been -enhanced with journaling. It supports the same options as ext2 as -well as the following additions: -.\" .TP -.\" .BR abort -.\" Mount the filesystem in abort mode, as if a fatal error has occurred. -.TP -.B journal=update -Update the ext3 filesystem's journal to the current format. -.TP -.B journal=inum -When a journal already exists, this option is ignored. Otherwise, it -specifies the number of the inode which will represent the ext3 filesystem's -journal file; ext3 will create a new journal, overwriting the old contents -of the file whose inode number is -.IR inum . -.TP -.BR journal_dev=devnum / journal_path=path -When the external journal device's major/minor numbers -have changed, these options allow the user to specify -the new journal location. The journal device is -identified either through its new major/minor numbers encoded -in devnum, or via a path to the device. -.TP -.BR norecovery / noload -Don't load the journal on mounting. Note that -if the filesystem was not unmounted cleanly, -skipping the journal replay will lead to the -filesystem containing inconsistencies that can -lead to any number of problems. -.TP -.BR data= { journal | ordered | writeback } -Specifies the journaling mode for file data. Metadata is always journaled. -To use modes other than -.B ordered -on the root filesystem, pass the mode to the kernel as boot parameter, e.g.\& -.IR rootflags=data=journal . -.RS -.TP -.B journal -All data is committed into the journal prior to being written into the -main filesystem. -.TP -.B ordered -This is the default mode. All data is forced directly out to the main file -system prior to its metadata being committed to the journal. -.TP -.B writeback -Data ordering is not preserved \(en data may be written into the main -filesystem after its metadata has been committed to the journal. -This is rumoured to be the highest-throughput option. It guarantees -internal filesystem integrity, however it can allow old data to appear -in files after a crash and journal recovery. -.RE -.TP -.B data_err=ignore -Just print an error message if an error occurs in a file data buffer in -ordered mode. -.TP -.B data_err=abort -Abort the journal if an error occurs in a file data buffer in ordered mode. -.TP -.BR barrier=0 " / " barrier=1 " -This disables / enables the use of write barriers in the jbd code. barrier=0 -disables, barrier=1 enables (default). This also requires an IO stack which can -support barriers, and if jbd gets an error on a barrier write, it will disable -barriers again with a warning. Write barriers enforce proper on-disk ordering -of journal commits, making volatile disk write caches safe to use, at some -performance penalty. If your disks are battery-backed in one way or another, -disabling barriers may safely improve performance. -.TP -.BI commit= nrsec -Sync all data and metadata every -.I nrsec -seconds. The default value is 5 seconds. Zero means default. -.TP -.B user_xattr -Enable Extended User Attributes. See the -.BR attr (5) -manual page. -.TP -.B acl -Enable POSIX Access Control Lists. See the -.BR acl (5) -manual page. -.TP -.BR usrjquota=aquota.user | grpjquota=aquota.group | jqfmt=vfsv0 -Apart from the old quota system (as in ext2, jqfmt=vfsold aka version 1 quota) -ext3 also supports journaled quotas (version 2 quota). jqfmt=vfsv0 -enables journaled quotas. For journaled quotas the mount options -usrjquota=aquota.user and grpjquota=aquota.group are required to tell the -quota system which quota database files to use. Journaled quotas have the -advantage that even after a crash no quota check is required. - -.SS "Mount options for ext4" -The ext4 filesystem is an advanced level of the ext3 filesystem which -incorporates scalability and reliability enhancements for supporting large -filesystem. - -The options -.B journal_dev, norecovery, noload, data, commit, orlov, oldalloc, [no]user_xattr -.B [no]acl, bsddf, minixdf, debug, errors, data_err, grpid, bsdgroups, nogrpid -.B sysvgroups, resgid, resuid, sb, quota, noquota, grpquota, usrquota -.B usrjquota, grpjquota and jqfmt -are backwardly compatible with ext3 or ext2. -.TP -.B journal_checksum -Enable checksumming of the journal transactions. This will allow the recovery -code in e2fsck and the kernel to detect corruption in the kernel. It is a -compatible change and will be ignored by older kernels. -.TP -.B journal_async_commit -Commit block can be written to disk without waiting for descriptor blocks. -If enabled, older kernels cannot mount the device. -This will enable 'journal_checksum' internally. -.TP -.BR barrier=0 " / " barrier=1 " / " barrier " / " nobarrier -These mount options have the same effect as in ext3. The mount options -"barrier" and "nobarrier" are added for consistency with other ext4 mount -options. - -The ext4 filesystem enables write barriers by default. -.TP -.BI inode_readahead_blks= n -This tuning parameter controls the maximum number of inode table blocks that -ext4's inode table readahead algorithm will pre-read into the buffer cache. -The value must be a power of 2. The default value is 32 blocks. -.TP -.BI stripe= n -Number of filesystem blocks that mballoc will try to use for allocation size -and alignment. For RAID5/6 systems this should be the number of data disks * -RAID chunk size in filesystem blocks. -.TP -.B delalloc -Deferring block allocation until write-out time. -.TP -.B nodelalloc -Disable delayed allocation. Blocks are allocated when data is copied from user -to page cache. -.TP -.BI max_batch_time= usec -Maximum amount of time ext4 should wait for additional filesystem operations to -be batch together with a synchronous write operation. Since a synchronous -write operation is going to force a commit and then a wait for the I/O -complete, it doesn't cost much, and can be a huge throughput win, we wait for a -small amount of time to see if any other transactions can piggyback on the -synchronous write. The algorithm used is designed to automatically tune for -the speed of the disk, by measuring the amount of time (on average) that it -takes to finish committing a transaction. Call this time the "commit time". -If the time that the transaction has been running is less than the commit time, -ext4 will try sleeping for the commit time to see if other operations will join -the transaction. The commit time is capped by the max_batch_time, which -defaults to 15000\ \[mc]s (15\ ms). This optimization can be turned off entirely by -setting max_batch_time to 0. -.TP -.BI min_batch_time= usec -This parameter sets the commit time (as described above) to be at least -min_batch_time. It defaults to zero microseconds. Increasing this parameter -may improve the throughput of multi-threaded, synchronous workloads on very -fast disks, at the cost of increasing latency. -.TP -.BI journal_ioprio= prio -The I/O priority (from 0 to 7, where 0 is the highest priority) which should be -used for I/O operations submitted by kjournald2 during a commit operation. -This defaults to 3, which is a slightly higher priority than the default I/O -priority. -.TP -.B abort -Simulate the effects of calling ext4_abort() for -debugging purposes. This is normally used while -remounting a filesystem which is already mounted. -.TP -.BR auto_da_alloc | noauto_da_alloc -Many broken applications don't use fsync() when -replacing existing files via patterns such as - -fd = open("foo.new")/write(fd,...)/close(fd)/ rename("foo.new", "foo") - -or worse yet - -fd = open("foo", O_TRUNC)/write(fd,...)/close(fd). - -If auto_da_alloc is enabled, ext4 will detect the replace-via-rename and -replace-via-truncate patterns and force that any delayed allocation blocks are -allocated such that at the next journal commit, in the default data=ordered -mode, the data blocks of the new file are forced to disk before the rename() -operation is committed. This provides roughly the same level of guarantees as -ext3, and avoids the "zero-length" problem that can happen when a system -crashes before the delayed allocation blocks are forced to disk. -.TP -.B noinit_itable -Do not initialize any uninitialized inode table blocks in the background. This -feature may be used by installation CD's so that the install process can -complete as quickly as possible; the inode table initialization process would -then be deferred until the next time the filesystem is mounted. -.TP -.B init_itable=n -The lazy itable init code will wait n times the number of milliseconds it took -to zero out the previous block group's inode table. This minimizes the impact on -system performance while the filesystem's inode table is being initialized. -.TP -.BR discard / nodiscard -Controls whether ext4 should issue discard/TRIM commands to the underlying -block device when blocks are freed. This is useful for SSD devices and -sparse/thinly-provisioned LUNs, but it is off by default until sufficient -testing has been done. -.TP -.B nouid32 -Disables 32-bit UIDs and GIDs. This is for -interoperability with older kernels which only -store and expect 16-bit values. -.TP -.BR block_validity / noblock_validity -This options allows to enables/disables the in-kernel facility for tracking -filesystem metadata blocks within internal data structures. This allows multi-\c -block allocator and other routines to quickly locate extents which might -overlap with filesystem metadata blocks. This option is intended for debugging -purposes and since it negatively affects the performance, it is off by default. -.TP -.BR dioread_lock / dioread_nolock -Controls whether or not ext4 should use the DIO read locking. If the -dioread_nolock option is specified ext4 will allocate uninitialized extent -before buffer write and convert the extent to initialized after IO completes. -This approach allows ext4 code to avoid using inode mutex, which improves -scalability on high speed storages. However this does not work with data -journaling and dioread_nolock option will be ignored with kernel warning. -Note that dioread_nolock code path is only used for extent-based files. -Because of the restrictions this options comprises it is off by default -(e.g.\& dioread_lock). -.TP -.B max_dir_size_kb=n -This limits the size of the directories so that any attempt to expand them -beyond the specified limit in kilobytes will cause an ENOSPC error. This is -useful in memory-constrained environments, where a very large directory can -cause severe performance problems or even provoke the Out Of Memory killer. (For -example, if there is only 512\ MB memory available, a 176\ MB directory may -seriously cramp the system's style.) -.TP -.B i_version -Enable 64-bit inode version support. This option is off by default. +.SS "Mount options for ext2, ext3 and ext4" +See the options section of the ext2(5), ext3(5) or ext4(5) man page (the e2fsprogs package must be installed). .SS "Mount options for fat" (Note: |