Restore performance LTO3 tapes in LTO5 drives.

[mrfokker]

I was wondering if when restoring data from LTO3 tape in a LTO 5 drive if restoring small amounts of data(mb) vs large (G) should take any longer. I did some lab testing doing various restores, since we will be migrating from an LTO3 tape library using Commvault8 to a new Library using LTO5 drives. To restore 200mb took 1.5 hours vs 12G taking 15 minutes. Is this normal?

 

[baddos]

Remember how the performance on LTO tapes goes up is by it's head density. So a LTO5 read/write will be faster than a LTO3 read/write because it is doing more in that single pass.

Now your times seem extreme. Make sure you are running 8.0 SP5 to ensure your new LTO5 drive is supported properly.

Also a selective restore might be tricky as you could be pulling data from different sections on the tape requires the tape to advance or rewind a lot before it gets to that data.

 

[mrfokker]

While I am running Commvault SP5 in my live enviroment I will have to go to the lab and double check the SP level.

 

[mrfokker]

I did check my lab and I was missing media agent and other SP's I will give it another try and see if I get any better results.

 

[mrfokker]

I installed the updates and still no change in the retore times.

 

[baddos]

If you do a full restore but redirect it to some temporary place, how is the speed? How is your LTO5 drive connected?

 

[mrfokker]

Unfortunately I do not have enough storage space to attempt to do a full restore in my lab(this is a 1tb backup) only 60G available. My connection to the tape library is SAS 6gbit and I get good read speeds 300G/hr of tape. When I do my lab restores I restore it directly to the Commserve which I have the Idataagent on because I do not have a client in the lab that represents the server that I am recovering from. I have a feeling that the larger the data I restore the better the performace will be due to the items you mentioned above.