Read-only mode mount

Some disk failures can result in the loss of enough metadata to make the entire file system unable to mount. In that event, it might be possible to preserve some user data through a read-only mode mount.

Attention: Attempt this only after you have tried to repair the file system with the mmfsck command.

This facility should be used only if a normal mount does not succeed, and should be considered a last resort to save some data after a fatal disk failure.

Read-only mode mount is invoked by using the mmmount command with the -o ro flags. After a read-only 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.