TSM V7.1 and NAS

Question 1

What is NDMP

Answer 1

a protocol invented by the NetApp and Legato companies, meant to transport data between network attached storage (NAS) devices and backup devices. This removes the need for transporting the data through the backup server itself, thus enhancing speed and removing load from the backup server.

Question 2

What is SnapDiff?

Answer 2

SnapDiff is an internal Data ONTAP engine that quickly identifies the file and directory differences between two Snapshot copies.

By finding the differences between two Snapshot copies, SnapDiff eliminates the file scanning requirements of a traditional backup application during an incremental backup, which reduces the backup processing to only the time it takes to write the changed or added data.

Question 3

What is SnapDiff API?

Answer 3

NetApp has provided a new API - the snapshot difference API, which takes two snapshots called base snapshot and diff snapshot as input, and returns a list of all files that have been added, deleted, modified and renamed between the two snapshots. The API can handles files, directories, ACL, streams, hard links, symbolic links etc. and supports both traditional and FlexVol volumes.

Question 4

What is Snapmirror to tape?

Answer 4

You can back up large NetApp file systems by using the NetApp SnapMirror to Tape feature. Using a block-level copy of data for backup, the SnapMirror to Tape method is faster than a traditional Network Data Management Protocol (NDMP) full backup and can be used when NDMP full backups are impractical.

Use the NDMP SnapMirror to Tape feature as a disaster recovery option for copying large NetAppfile systems to auxiliary storage. For most NetAppfile systems, use the standard NDMP full or differential backup method.

Using a parameter option on the BACKUP NODE and RESTORE NODE commands, you can back up and restore file systems by using SnapMirror to Tape. There are several limitations and restrictions on how SnapMirror images can be used. Consider the following guidelines before you use it as a backup method:

You cannot initiate a SnapMirror to Tape backup or restore operation from the Tivoli® Storage Manager Operations Center, web client, or command-line client.
You cannot perform differential backups of SnapMirror images.
You cannot perform a directory-level backup using SnapMirror to Tape, thus Tivoli Storage Manager does not permit an SnapMirror to Tape backup operation on a server virtual file space.
You cannot perform an NDMP file-level restore operation from SnapMirror to Tape images. Therefore, a table of contents is never created during SnapMirror to Tape image backups.
At the start of a SnapMirror to Tape copy operation, the file server generates a snapshot of the file system. NetAppprovides an NDMP environment variable to control whether this snapshot should be removed at the end of the SnapMirror to Tape operation. Tivoli Storage Manager always sets this variable to remove the snapshot.
After a SnapMirror to Tape image is retrieved and copied to a NetAppfile system, the target file system is left configured as a SnapMirror partner. NetAppprovides an NDMP environment variable to control whether this SnapMirror relationship should be broken. Tivoli Storage Manager always “breaks” the SnapMirror relationship during the retrieval. After the restore operation is complete, the target file system is in the same state as that of the original file system at the point-in-time of backup.