xfs_admin(8)                                                                                                        xfs_admin(8)



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)