xfs_admin - change parameters of an XFS filesystem
] [ -c 0
] [ -L
] [ -U uuid
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
parameters. A number of parameters of a mounted filesystem can be examined and
modified using the xfs_growfs(8)
- Enables unwritten extent support on a filesystem that does not already
have this enabled (for legacy filesystems, it can't be disabled anymore at
- Specifies that the filesystem image to be processed is stored in a regular
file at device (see the mkfs.xfs -d file
- Enables version 2 log format (journal format supporting larger log
- Print the current filesystem label.
- Enable 32bit project identifier support (PROJID32BIT feature).
- Print the current filesystem UUID (Universally Unique IDentifier).
- -c 0|1
- Enable (1) or disable (0) lazy-counters in the filesystem. This operation
may take quite a bit of time on large filesystems as the entire filesystem
needs to be scanned when this option is changed.
- With lazy-counters enabled, the superblock is not modified or logged on
every change of the free-space and inode counters. Instead, enough
information is kept in other parts of the filesystem to be able to
maintain the counter values without needing to keep them in the
superblock. This gives significant improvements in performance on some
configurations and metadata intensive workloads.
- -L label
- Set the filesystem label to label. XFS filesystem labels can be at
most 12 characters long; if label is longer than 12 characters,
xfs_admin will truncate it and print a warning message. The
filesystem label can be cleared using the special "--"
value for label.
- -U uuid
- 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 UUID to the null
UUID. The uuid may also be generate, which will generate a
new UUID for the filesystem.
- Prints the version number and exits.
manual entry describes how to mount a filesystem using its
label or UUID, rather than its block special device name.