MSA2312fc Hardware RAID slower than Win 2008 Software RAID

[A. Hassan]

Hi All,

I am using Windows 2008 64-bit. It appears that the Windows software RAID is much faster than the hardware RAID provided by the HP MSA 2312FC. I tried RAID-0 and RAID-5 and the software RAID is still better than MSA hardware RAID.

I am comparing:
Disk_A: is a 5 drives hardware RAID-0
Disk_B: is 5 drives software RAID. The drives are in the MSA enclosures but they are RAIDed through the Windows software RAID.

Disk_B is coming up faster than Disk_A. Around 15%-20 faster from random reads using 4096 bytes-blocks and the MSA performance gets worse as I inrease the block sizes! I would have expected Disk_B (software) to be slower or is that a known problem with the MSA?

My HBA driver had a maximum queue depth of "16" per LUN. I raised it to "80" and the performance increased but still the software is outperforming the MSA hardware RAID.

To also rule out RAID-0 being the problem. I tried RAID-5 and the results are still disappointing.

The table below shows the I/O counts from IOMeter using an 8GB file reading 4KB with 20,40, and 60 outstanding requests. As you can see both arrays are almost the same and surprisingly the Software (SW) RAID is 10% faster!! When I change the mix to be 30% write and 70% read, both arrays are identical in performance. I would have expected the MSA RAID would be faster but seems it is consistently slower than SW RAID

__________________20_________40___________60
SW-RAID5__________937________1074_________1135
HW-RAID5__________849________949__________993


Would anyone have any thoughts on what is happening or suggestion on what I can try out?

Thanks,

Ahmed

[Mapi]

Hi Ahmed,

I agree with your problem, I have exactly the same with a MSA2324FC. I did a lot of tests and I find out that its a problem with larger files. Did you try to copy a large file (> 3GB) to the MSA? Maybe you can tell me what happend than.
I also open a tread with that problem but still have no answer.

Best regards,
Markus