Restoring a file system from a snapshot

Use the mmrestorefs command to restore user data and attribute files in an active file system from a snapshot.

Prior to issuing the mmrestorefs command, ensure that the file system is mounted. When restoring from an independent fileset snapshot, ensure that the fileset is in linked state.

Existing snapshots, including the one being used in the restore, are not modified by the mmrestorefs command. To obtain a snapshot of the restored file system, you must issue the mmcrsnapshot command to capture it before issuing the mmrestorefs command again.

As an example, suppose that you have a directory structure similar to the following: 
/fs1/file1
/fs1/userA/file2
/fs1/userA/file3
/fs1/.snapshots/snap1/file1
/fs1/.snapshots/snap1/userA/file2
/fs1/.snapshots/snap1/userA/file3
If the directory userA is then deleted, the structure becomes similar to this: 
/fs1/file1
/fs1/.snapshots/snap1/file1
/fs1/.snapshots/snap1/userA/file2
/fs1/.snapshots/snap1/userA/file3
The directory userB is then created using the inode originally assigned to userA, and another snapshot is taken: 
mmcrsnapshot fs1 snap2
The output is similar to this: 
Writing dirty data to disk.
Quiescing all file system operations.
Writing dirty data to disk again.
Snapshot snap2 created with id 2.
The resulting directory structure is similar to the following: 
/fs1/file1
/fs1/userB/file2b
/fs1/userB/file3b
/fs1/.snapshots/snap1/file1
/fs1/.snapshots/snap1/userA/file2
/fs1/.snapshots/snap1/userA/file3
/fs1/.snapshots/snap2/file1
/fs1/.snapshots/snap2/userB/file2b
/fs1/.snapshots/snap2/userB/file3b
The file system is then restored from snap1: 
mmrestorefs fs1 snap1
The resulting directory structure is similar to the following: 
/fs1/file1
/fs1/userA/file2
/fs1/userA/file3
/fs1/.snapshots/snap1/file1
/fs1/.snapshots/snap1/userA/file2
/fs1/.snapshots/snap1/userA/file3
/fs1/.snapshots/snap2/file1
/fs1/.snapshots/snap2/userB/file2b
/fs1/.snapshots/snap2/userB/file3b

For complete usage information, see mmrestorefs command.