NAME¶
fsfreeze - suspend access to a filesystem (Ext3/4, ReiserFS, JFS, XFS)
SYNOPSIS¶
fsfreeze --freeze|
--unfreeze mountpoint
DESCRIPTION¶
fsfreeze suspends or resumes access to a filesystem.
fsfreeze halts any 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 a filesystem on the device when
a snapshot creation is requested. For more details see the
dmsetup(8)
man page.
The
mountpoint argument is the pathname of the directory where the
filesystem is mounted. The filesystem must be mounted to be frozen (see
mount(8)).
Note that access-time updates are also suspended if the filesystem is mounted
with the traditional atime behavior (mount option
strictatime, for more
details see
mount(8)).
OPTIONS¶
- -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.
- -V, --version
- Display version information and exit.
- -h, --help
- Display help text and exit.
AUTHOR¶
Written by Hajime Taira.
NOTES¶
This man page is based on
xfs_freeze(8).
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/.