FSFREEZE(8)                                                                                                          FSFREEZE(8)



NAME
       fsfreeze - suspend access to an filesystem (Linux Ext3/4, ReiserFS, JFS, XFS).

SYNOPSIS
       fsfreeze -f mountpoint

       fsfreeze -u mountpoint


DESCRIPTION
       fsfreeze suspends and resumes access to an filesystem

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

       fsfreeze is unncessary for device-mapper devices. The device-mapper (and LVM) automatically  freezes  filesystem  on  the
       device when a snapshot creation is requested.  For more details see the dmsetup(8) man page.

       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)).

OPTIONS
       -h, --help
              Print help and exit.

       -f, --freeze
              This option requests the specified a 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.

       -u, --unfreeze
              This  option  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.

AUTHOR
       Written by Hajime Taira.

NOTES
       This man page based on xfs_freeze.  One of -f or -u must be supplied to fsfreeze.

SEE ALSO
       mount(8)

AVAILABILITY
       The   fsfreeze   command   is   part   of   the   util-linux-ng   package   and   is   available   from    ftp://ftp.ker-
       nel.org/pub/linux/utils/util-linux-ng/.




                                                            May 2010                                                 FSFREEZE(8)