DL360p G8 and Smart Array P430 RAID1 much poorer performance than a single disk

[Markus Angerer]

Hi, 

I hope somebody could help me find out whether I have a technical problem or my thoughts are just wrong:

I have a Proliant DL360p Gen8 upgraded with a P430/4GB SAS 12G controller. Attached to it are HGST SAS SSD. At first I connected one single SSD and had a constant data rate of 510MB/s - now I connected a second drive and put them into a RAID1 (mirrored) array and suddenly the throughput is down to 170 MB/s.

I did expect a bit of a loss due to the overhead of reading/writing from two disks but didn't expect more than a few percent and not a complete disaster. 

 The one thing I found out and worries me is that in SSA (Smart Storage Administrator) the Cache Options were configurable and set to Read 15/ Write 85% with the single disk. Now with two disks it suddenly says "Cache n ot configured", doesn't show any configurable options and is set to Read 100% / Write 0%. But even reading is painfully slow.

The battery is connected, fully charged and ok. Array initialisation is competed. (according to SSA). 

Does anyone have an idea what I'm doing wrong here?

Thanks a lot in advance!

Markus

[Bunsol]

Hi Markus,

Cache will not make a difference for having one drive or two drives. Check the firmware of the drive and the controller, check reseat the cabling, try it on a similar setup to check issue with drives or something else. If the issue is beyond this then it needs to be checked at hardware level hence request you to log a case with us at our portal below:-

https://support.hpe.com/hpesc/public/home

[Markus Angerer · Accepted solution]

Hi, thanks for you message.

After playing a bit with my machine I did find what makes the difference (at least for me): HP SSD SmartPath. Once I disable it I get a much better performance out of my disks. It is now even up to 750MB/s :-)