.TH xfs_admin 8
.SH NAME
xfs_admin \- change parameters of an XFS filesystem
.SH SYNOPSIS
.B xfs_admin
[
.B \-eflu
] [
.B \-L
.I label
] [
.B \-U
.I uuid
]
.I device
.SH DESCRIPTION
.B xfs_admin
uses the
.BR xfs_db (8)
command to modify various parameters of a filesystem.
.PP
Devices that are mounted cannot be modified.
Administrators must unmount filesystems before
.BR xfs_admin " or " xfs_db (8)
can convert parameters.
A number of parameters of a mounted filesystem can be examined
and modified using the
.BR xfs_growfs (8)
command.
.SH OPTIONS
.TP
.B \-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).
.TP
.B \-f
Specifies that the filesystem image to be processed is stored in a
regular file at
.I device
(see the
.B mkfs.xfs \-d
.I file
option).
.TP
.B \-j
Enables version 2 log format (journal format supporting larger
log buffers).
.TP
.B \-l
Print the current filesystem label.
.TP
.B \-u
Print the current filesystem UUID (Universally Unique IDentifier).
.TP
.BI \-L " label"
Set the filesystem label to
.IR label .
XFS filesystem labels can be at most 12 characters long; if
.I label
is longer than 12 characters,
.B xfs_admin
will truncate it and print a warning message.
The filesystem label can be cleared using the special "\c
.B \-\-\c
" value for
.IR label .
.TP
.BI \-U " uuid"
Set the UUID of the filesystem to
.IR uuid .
A sample UUID looks like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16".
The
.I uuid
may also be
.BR nil ,
which will set the filesystem UUID to the null UUID.
The
.I uuid
may also be
.BR generate ,
which will generate a new UUID for the filesystem.
.PP
The
.BR mount (8)
manual entry describes how to mount a filesystem using its label or UUID,
rather than its block special device name.
.SH SEE ALSO
.BR mkfs.xfs (8),
.BR mount (8),
.BR xfs_db (8),
.BR xfs_growfs (8),
.BR xfs (5).