xfs_freeze(8)                        System Manager's Manual                        xfs_freeze(8)



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 sup‐
       port 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 com‐
       plete.

       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)