NAME
xfs_admin - change parameters of an XFS filesystem
SYNOPSIS
xfs_admin [ -eflu ] [ -c 0|1 ] [ -L label ] [ -U uuid ] device
DESCRIPTION
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. A number of parameters of a mounted filesystem can be
examined and modified using the xfs_growfs(8) command.
OPTIONS
-e 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).
-f Specifies that the filesystem image to be processed is stored in
a regular file at device (see the mkfs.xfs -d file option).
-j Enables version 2 log format (journal format supporting larger
log buffers).
-l Print the current filesystem label.
-u 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.
The mount(8) manual entry describes how to mount a filesystem using its
label or UUID, rather than its block special device name.
SEE ALSO
mkfs.xfs(8), mount(8), xfs_db(8), xfs_growfs(8), xfs_repair(8), xfs(5).
xfs_admin(8)