DDM to LTO5 stgpool backup performance

[ChrisRees]

Hi

So we're quite a new DataDomain user. We have a DD4500 running as a VTL talking to an AIX TSM Server all over 8Gb Fibre channel.

My question is for others running a similar setup, what kind of performance do you get when doing stgpool backups from the DDM to LTO5 tape ?

I have 2 FC ports on the TSM Server zoned to two ports on the DDM and LTO5 drives spread over 4 other FC adapters.

If I do a 6 process stgpool backup from DDM to 6 LTO5 drives I struggle to get over 400Mb/sec, usually around 350Mb/sec.
This is when there are no other TSM server side processes running and no client backups or restores.

I have to get my offsite tapes ready for 11am for a courier so need much better stgpool backup throughput.

If anyone has any reallife examples that would be great.

Thanks

 

[rgg]

Well, the theoretical max for lto-5 uncompressed is ~150 megabytes/sec. 100-120 is more common. If you've got 6 drives, then 6-700 is probably the expected aggregate, minus TSM processing costs...so I'd say 5-600 is probably a good target to shoot for.

Sounds like it's time for you to collect some performance doc to see where the bottleneck is.