NAME | SYNOPSIS | DESCRIPTION | OPTIONS | FILESYSTEM SUPPORT | NOTES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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FSFREEZE(8) System Administration FSFREEZE(8)
fsfreeze - suspend access to a filesystem (Ext3/4, ReiserFS, JFS, XFS)
fsfreeze --freeze|--unfreeze mountpoint
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)).
-f, --freeze This option requests the specified filesystem to be frozen from new modifications. When this is selected, all ongoing transactions in the filesystem are allowed to complete, new write(2) 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. -h, --help Display help text and exit. -V, --version Print version and exit.
This command will work only if filesystem supports has support for freezing. List of these filesystems include (2016-12-18) btrfs, ext2/3/4, f2fs, jfs, nilfs2, reiserfs, and xfs. Previous list may be incomplete, as more filesystems get support. If in doubt easiest way to know if a filesystem has support is create a small loopback mount and test freezing it.
This man page is based on xfs_freeze(8).
Written by Hajime Taira.
mount(8)
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
The fsfreeze command is part of the util-linux package which can
be downloaded from Linux Kernel Archive
<https://www.kernel.org/pub/linux/utils/util-linux/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to man-pages@man7.org
util-linux 2.39.594-1e0ad 2023-07-19 FSFREEZE(8)