SnapMirror-2-Tape for LOW bandwidth

SMTape is a high performance disaster recovery solution from Data ONTAP that backs up blocks of data to tape. It is Snapshot copy-based backup to tape feature. This feature is available only in the Data ONTAP 8.0 7-Mode or later releases.

You can use SMTape to perform volume backups to tapes. However, you cannot perform a backup at the qtree or subtree level. Also, you can perform only a level-0 backup and not incremental backups.
When you perform an SMTape backup, you can EITHER specify the name of the Snapshot copy to be backed up to tape. When you specify a Snapshot copy for the backup, all the Snapshot copies older than the specified Snapshot copy are also backed up to tape. If do not specify any snapshot, smtape creates a base snapshot copy to be used later for tape seeding.

What tape seeding is ?

Tape seeding is an SMTape functionality that helps you intialize the destination storage system in a volume SnapMirror relationship.

Consider a scenario in which you want to establish a SnapMirror relationship between a source system and a destination system over a low-bandwidth connection. Incremental mirroring of Snapshot copies from the source to the destination is feasible over a lowband width connection. However, an initial mirroring of the base Snapshot copy would take a long time over a low-bandwidth connection. In such a case, you can perform an SMTape backup of the source volume to a tape and use the tape to transfer the initial base Snapshot copy to the destination. You can then set up incremental SnapMirror updates to the destination system using the low-bandwidth connection.

Test it out on - Ontap SIMULATOR  

 

Simulator provides simulated tape devices which can be used to simulate smtape feature.

 

filerA>sysconfig -t

or

filerA>storage stats tape

 

This will list the test tape drives bundled with ontap.

 

You can perform an SMTape backup and restore using NDMP-compliant backup applications or using the Data ONTAP 8.0 7-Mode smtape backup and smtape restore CLI commands.

 

Steps:

1. snapmirror 2 tape:



 



2. Restore to volume (seeding back > destination volume)

te



3. Resume incremental snapmirror update to destination volume



Note: In this demo, I have used both snapmirror souce & destination volumes on the same filer but the logic remains same.