Storevault S500 performance

[Zink71]

Greeting -

I am a somewhat small shop - 50 users, and looking at the Storevault line, which I hink would be perfact, BUT I am worried about the slower 7200 Sata disks. I read that that one test showed the S500 doing 65MB/s on reads and 43 on writes; How does this stack up against direct Attached storage ?

 

[xmsre]

S500 - single controller, dual power supplies, up to 12 drives.

Yes, a 7200 RPM SATA Drive gets about 40 IOPS/spindle (at a 20ms response time). If you comapre this to 10K SCSI, the SCSI drives get about 85 IOPS/spindle (at a 20ms response time). The value the S500 provides is at the virtualization layer - there is no write penalty like there is with RAID 10 ( a write penalty of 2) or RAID 5 (a write penalty of 4).

Lets suppose I take all 12 drives and put them in a RAID DP raid group, that group in an aggregate, and from that aggregate carve a single volume containing a single LUN. My IO performance would be 400 IOPS.

Now lets suppose I take 12 10 SCSI spindles on DAS and create a RAID 5 array. My write performance is 233 IOPS, and my read performance is 935 IOPS. If I assume a 1:1 read write ratio my mixed performance is 534 IOPS. Of course that number varies depending on the read:write ratio of the application placing the load.


The SATA drives are generally going to provide more space than the SCSI drives, and the SCSI DAS will likely be more expense than an S500. With only 50 users, I'd be confident that the solution would provide adequate performance for home directories or even messaging (exchange up to a couple several IOPS/user which is a very heavy mail profile). It probably wouldn't be ideal for databases with heavy OLAP activity.

 

[Zink71]

Hi xmsre,

This information you have provided is very valuable, amd I really appreciate it! Because the Storevault is kind of new, there is not a lot of performance information on it.

I think I can do it for Excahnge. I do have a MS SQL database that gets pretty heavy use, Currently on a dell 2850 w/ 5 10K disks @ Raid5. Sounds like the storevault will probably beat that. If it does, then this is sufficient.

The Storevault does offer a Fiber option, but the Sales Engineer tells me it will do almost nothing to help my performance. Would you concur ?

 

[xmsre]

I would concur. If you want to increase performance you'll need to step up to something like a FAS270.

With 10 10K drives in RAID 10 you have write performance of 191 IOPS and read performace of 765 IOPS. Assuming a read to write ratio of 1:1, your mixed performance is 478 IOPS. You should be able to match this number with the S500.

For SQl if OLTP, then you have a fair proportion of writes and you'll likely be better off with the S500. If it's an OLAP workload, then it's mostly reads and you may consider leaving it on RAID 5