NAME

       xfs_freeze - suspend access to an XFS filesystem

SYNOPSIS

       xfs_freeze [ -f | -u ] mount-point
       xfs_freeze -V

DESCRIPTION

       xfs_freeze suspends and resumes access to an XFS filesystem (see xfs(5)).

       xfs_freeze halts new access to the filesystem and creates a stable image on disk.  xfs_freeze is intended
       to be used with volume managers and hardware RAID devices that support the creation of snapshots.

       The  mount-point  argument  is  the  pathname  of  the  directory  where  the filesystem is mounted.  The
       filesystem must be mounted to be frozen (see mount(8)).

       The -f flag requests the specified XFS filesystem to be frozen from  new  modifications.   When  this  is
       selected,  all ongoing transactions in the filesystem are allowed to complete, new write system calls are
       halted, other calls which modify the filesystem are  halted,  and  all  dirty  data,  metadata,  and  log
       information  are  written  to  disk.  Any process attempting to write to the frozen filesystem will block
       waiting for the filesystem to be unfrozen.

       Note that even after freezing, the on-disk filesystem can contain information on files that are still  in
       the  process  of unlinking.  These files will not be unlinked until the filesystem is unfrozen or a clean
       mount of the snapshot is complete.

       The -u flag is used to un-freeze the  filesystem  and  allow  operations  to  continue.   Any  filesystem
       modifications that were blocked by the freeze are unblocked and allowed to complete.

       The -V flag prints the version number and exits.

       Unless -V is specified, one of -f or -u must be supplied to xfs_freeze.

NOTES

       A  copy of a frozen XFS filesystem will usually have the same universally unique identifier (UUID) as the
       original, and thus may be prevented from being mounted.  The XFS nouuid  mount  option  can  be  used  to
       circumvent this issue.

       In  Linux  kernel version 2.6.29, the interface which XFS uses to freeze and unfreeze was elevated to the
       VFS, so that this tool can now be used on many other Linux filesystems.

SEE ALSO

       xfs(5), lvm(8), mount(8).

                                                                                                   xfs_freeze(8)