Automatic file system recovery

File Service Administration Guide for Hitachi NAS Platform

Version
14.9.x
Audience
anonymous
Part Number
MK-92HNAS006-31

The fixfs utility is the main file system recovery tool, but it should only be used under the supervision of customer support personnel.

fixfs is capable of repairing a certain amount of non-critical metadata, for example performing orphan recovery. At all stages that have the potential to last longer than a few minutes, fixfs provides progress reporting, and the option to abort the fix. Note that progress reports are stage or operation based, for example Stage 3 of 7 complete. For some operations, fixfs will also provide an estimate of time until the completion of the operation.

The strategy used by fixfs to repair file systems can be summarized as:

  • fixfs or fs-checkpoint-health are the recovery tools to be used if a file system is experiencing corruption. The default fixfs behavior may be modified by various command line switches, but often the required switch is suggested by fixfs during or at the end of a previous run.
  • Where possible, fixfs will run with the file system in any state (there will be no need to perform file system recovery first, so that there's no need to worry about what happens if recovery cannot complete due to corruption). Where not possible (for example, if the file system is marked as "failed" or "requires expansion"), fixfs will not run. When fixfs does not run, it will give a clear indication of what needs to be done to get to the point where it can run.
  • By default, fixfs will only modify those objects which are lost or corrupted.
  • By default, fixfs will only bring the file system to the point where it can be mounted.
  • Snapshots are considered expendable and are deleted.