FSFREEZE(8) - phpMan

FSFREEZE(8) System Administration FSFREEZE(8)

NAME
fsfreeze - suspend access to a filesystem (Linux Ext3/4, ReiserFS, JFS, XFS)

SYNOPSIS
fsfreeze --freeze|--unfreeze 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) automati-
cally 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)).

Note that access time updates are also suspends if the filesystem is mounted with the tra-
ditional atime semantics (mount option strictatime, for more details see mount(8)).

OPTIONS
-h, --help
Print help and exit.

-f, --freeze
This option requests the specified a filesystem to be frozen from new modifica-
tions. 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
Show version number and exit.

AUTHOR
Written by Hajime Taira.

NOTES
This man page based on xfs_freeze. One of -f or -u must be supplied to fsfreeze.