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)