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 mkfs time).
- Specifies that the filesystem image to be processed is
stored in a regular file at device (see the mkfs.xfs -d
- Enables version 2 log format (journal format supporting
larger log buffers).
- Print the current filesystem label.
- Enable 32bit project identifier support (PROJID32BIT
- Print the current filesystem UUID (Universally Unique
- -c 0|1
- Enable (1) or disable (0) lazy-counters in the
- Lazy-counters may not be disabled on Version 5 superblock
filesystems (i.e. those with metadata CRCs enabled).
- This operation may take quite a bit of time on large
filesystems as the entire filesystem needs to be scanned when this option
- 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. Note that on CRC-enabled
filesystems, this will set an incompatible flag such that older kernels
will not be able to mount the filesystem. To remove this incompatible
flag, use restore, which will restore the original UUID and remove
the incompatible feature flag as needed.
- 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.