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       xfs_admin - change parameters of an XFS filesystem


       xfs_admin [ -eflu ] [ -c 0|1 ] [ -L label ] [ -U uuid ] device


       xfs_admin  uses the xfs_db(8) command to modify various parameters of a

       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.


       -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

       -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

              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.


       mkfs.xfs(8), mount(8), xfs_db(8), xfs_growfs(8), xfs_repair(8), xfs(5).