xfs_freeze(8) - man - phpMan

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 support  the  cre‐
       ation 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  ele‐
       vated 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)