NAME

       fsfreeze - suspend access to a 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 unnecessary 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    package    and    is    available    from
       ftp://ftp.kernel.org/pub/linux/utils/util-linux/.