xfs_freeze(1M)

NAME
     xfs_freeze - suspend access to an XFS filesystem

SYNOPSIS
     xfs_freeze -f|-u mount-point

DESCRIPTION
     xfs_freeze suspends and resumes access to an XFS filesystem.

     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 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 and
     can not be the root filesystem.

     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 attemting
     to write to the frozen filesystem will be blocked waiting for the
     filessytem to be unfrozen.

     Note that even after freezing, some files may still be in the process of
     being unlinked.  These files are noted in the disk image and the
     unlinking will be completed after the filesystem is unfrozen or a
     mount(1m) of the snapshot is done.

     The -u option is used to unfreeze the filesystem and allow operations to
     continue.  Any filesystem modifications that were blocked by the freeze
     are unblocked and allowed to complete.

     One of -f or -u must be supplied to xfs_freeze.

SEE ALSO
     mount(1m).