VLS9000 write performance

[ddaloia]

Hi Folks,

Just getting started with the VLS9000 and we notice any backups we write to tape max out at 100MB/s. This happens no matter how many servers, jobs, or tapes we are writing to at one time. It is a single node system which HP advertises as capable of 550MB/s with no compression or 600MB/s with 2:1 compression.

My question is what are other folks getting for performance and what are some things I can do to get better performance?

Just to add, the backup storage node is a BL460G6, 2-4core 5570 procs, 6GB mem, dual 10GbE nics. All other servers we are backing up are similar, only way more memory. Tested backups with Data Protector and EMC Networker.

P.S. This thread has been moevd from Tape Libraries and Drives to Disk-Based Backup. - Hp Forum moderator

[Marino Meloni_1]

Hi,
where did you got these figure?
I thought the max speed with only one single array without dedup was max 240 MB/sec
and with dedup (FW 3.x.x) max 150 MB/s
You should considere also limitation due to the source of the data, the SAN path, etc...

[ddaloia]

I think you are confusing the D2D Arrays with the VLS. Data Dedup is not done during transfer on the VLS, it is done after a full cartridge is written to so it does not affect performance of writes at all. You can find the specs at http://h18000.www1.hp.com/products/quickspecs/12812_div/12812_div.HTML.

I have found by adding more (virtual) tape drives to the (virtual) ESL Library and forcing more streams from the backup client has improved performance so far to almost 300MB/s. I am still doing some testing so I will post back with the results if anyone is interested.

[Kyle Weir]

Just as an FYI, I've had a fair amount of experience with dedup on the 6000's (I'm upgrading to a 9000 today) and it's full tapes that get deduped. To reduce this I usually use one drive at a time for a backup to enable the best dedup performance. As I grow our backups, I can see that writing to more then one tape at a time may not really hurt the deduping. But if you were writing to 2 tapes at once you'll need to fill both tapes before it'll dedup that backup at all. For a large backup this may not be bad especially if you filled it up daily. But otherwise it could be a problem.