Linux "xfs_admin" Command Line Options and Examples

change parameters of an XFS filesystem

xfs_admin uses the xfs_db(8) command to modify various parameters of a filesystem. Devices that are mounted cannot be modified. Administrators must unmount filesystems before xfs_admin or xfs_db(8) can convert parameters.

Usage:

xfs_admin [ -eflpu ] [ -c 0|1 ] [ -L label ] [ -U uuid ] device xfs_admin -V

Related Commands

Command Line Options:

-j

Enables version 2 log format (journal format supporting larger log buffers).


                            xfs_admin -j ...

-l

Print the current filesystem label.


                            xfs_admin -l ...

-p

Enable 32bit project identifier support (PROJID32BIT feature).


                            xfs_admin -p ...

-u

Print the current filesystem UUID (Universally Unique IDentifier).


                            xfs_admin -u ...

-c

Lazy-counters may not be disabled on Version 5 superblock filesystems (i.e. those with metadata CRCsenabled).This operation may take quite a bit of time on large filesystems as the entire filesystem needs to bescanned when this option is changed.With lazy-counters enabled, the superblock is not modified or logged on every change of the free-spaceand inode counters. Instead, enough information is kept in other parts of the filesystem to be able tomaintain the counter values without needing to keep them in the superblock. This gives significantimprovements in performance on some configurations and metadata intensive workloads.


                            xfs_admin -c ...

-L

Set the filesystem label to label. XFS filesystem labels can be at most 12 characters long; if labelis longer than 12 characters, xfs_admin will truncate it and print a warning message. The filesystemlabel can be cleared using the special "--" value for label.


                            xfs_admin -L ...

-U

Set the UUID of the filesystem to uuid. A sample UUID looks like this:"c1b9d5a2-f162-11cf-9ece-0020afc76f16". The uuid may also be nil, which will set the filesystem UUIDto the null UUID. The uuid may also be generate, which will generate a new UUID for the filesystem.Note that on CRC-enabled filesystems, this will set an incompatible flag such that older kernels willnot be able to mount the filesystem. To remove this incompatible flag, use restore, which will restorethe original UUID and remove the incompatible feature flag as needed.


                            xfs_admin -U ...

-V

The mount(8) manual entry describes how to mount a filesystem using its label or UUID, rather than its blockspecial device name.


                            xfs_admin -V ...