4.12. Repairing a File System
When nodes fail with the file system mounted, file-system journaling allows fast recovery. However, if a storage device loses power or is physically disconnected, file-system corruption may occur. (Journaling cannot be used to recover from storage subsystem failures.) When that type of corruption occurs, you can recover the GFS file system by using the gfs_fsck command.
The gfs_fsck command must only be run on a file system that is unmounted from all nodes.
The gfs_fsck command has changed from previous releases of Red Hat GFS in the following ways:
You can no longer set the interactive mode with Ctrl-C. Pressing Ctrl-C now cancels the gfs_fsck command. Do not press Ctrl-C unless you want to cancel the command.
You can increase the level of verbosity by using the -v flag. Adding a second -v flag increases the level again.
You can decrease the level of verbosity by using the -q flag. Adding a second -q flag decreases the level again.
The -n option opens a file system as read-only and answers no to any queries automatically. The option provides a way of trying the command to reveal errors without actually allowing the gfs_fsck command to take effect.
Refer to the gfs_fsck man page, gfs_fsck(8), for additional information about other command options.
gfs_fsck -y BlockDevice
The -y flag causes all questions to be answered with yes. With the -y flag specified, the gfs_fsck command does not prompt you for an answer before making changes.
Specifies the block device where the GFS file system resides.
In this example, the GFS file system residing on block device /dev/vg01/lvol0 is repaired. All queries to repair are automatically answered with yes.
gfs_fsck -y /dev/vg01/lvol0