Restricted mode mount
GPFS provides a capability to mount a file system in a restricted mode when significant data structures have been destroyed by disk failures or other error conditions.
Restricted mode mount is not intended for normal operation, but may allow the recovery of some user data. Only data which is referenced by intact directories and metadata structures would be available.
- Follow the procedures in Information to be collected before contacting the IBM Support Center, and then contact the IBM Support Center before using this capability.
- Attempt this only after you have tried to repair the file system with the mmfsck command. (See Why does the offline mmfsck command fail with "Error creating internal storage"?.)
- Use this procedure only if the failing disk is attached to an AIX® or Linux® node.
Some disk failures can result in the loss of enough metadata to render the entire file system unable to mount. In that event it might be possible to preserve some user data through a restricted mode mount. This facility should only be used if a normal mount does not succeed, and should be considered a last resort to save some data after a fatal disk failure.
Restricted mode mount is invoked by using the mmmount command with the -o rs flags. After a restricted mode mount is done, some data may be sufficiently accessible to allow copying to another file system. The success of this technique depends on the actual disk structures damaged.