xfs_freeze - suspend access to an XFS filesystem
suspends and resumes access to an XFS filesystem (see
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.
argument is the pathname of the directory where the
filesystem is mounted. The filesystem must be mounted to be frozen (see
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
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 complete.
flag prints the version number and exits.
is specified, one of -f
must be supplied to
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
In Linux kernel version 2.6.29, the interface which XFS uses to freeze and
unfreeze was elevated to the VFS, so that this tool can now be used on many
other Linux filesystems.