TSM for VE requires full backup?

[ekos]

Hi

We have 500+ VMs and we consider using TSM for VE for backup. Can you do incrementals forever with TSM for VE or do you need to make full VM backups once in a while? Making full backups of 500+ VMs let's say each two weeks or month isn't an easy job.

Thanks

 

[drivechip]

Hi ekos

No you can't make incrementals forever. The recommodation of IBM is to perform a full backup at least after 14 incremental backups. It is written somewhere in the user guide.

Weekly full is quiet easy to schedule. You just need 14 schedulers. Please consider a appropriate number of vStorage servers and their sizing.

 

[tobi007]

The next version which come in Q4/2012 should can incremental forever!

 

[FastBackTSMUK]

The next version which come in Q4/2012 should can incremental forever!

If it does then it will still need to perform a full to start with. I imagine that a 'synthetic full' we be performed as a post process on the TSM server.

 

[drivechip]

The next version which come in Q4/2012 should can incremental forever!

Yes, I've heard from that. It was on the roadmap. I'm a bit skeptical especially regarding restore performance when using tapes. It might better work with a VTL or for disk based backups. We will see.

 

[FastBackTSMUK]

Yes, I've heard from that. It was on the roadmap. I'm a bit skeptical especially regarding restore performance when using tapes. It might better work with a VTP or for disk based backups. We will see.

There's documented limitations for using tape, specifically the near instant restores of volumes. Disk/VTL works best, especially when attempting to save space with de-duplication.

 

[tobi007]

What are your experience with Full VM-Restore from type?
I think its much slower than from disk.

 

[moon-buddy]

What are your experience with Full VM-Restore from type?
I think its much slower than from disk.

Tape is slow. TSM for VE 6.2.2 had issues on the way the files were stored on tape. The structure was CTL-DAT-CTL-DAT-CTL etc. This required a heck of a long time to restore.

IBM had a work around by separating the CTL and DAT files as written to two tapes. This sped up the restore. The issue is not so noticeable with disk as disk is fast and radom. Tape is sequential.