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/.