topic Re: P4000 noob questions in StoreVirtual Storage

P4000 noob questions

BuddyD — Mon, 16 Sep 2013 03:00:20 GMT

Hi folks,

We have a 3-node HP DL380 G7 cluster ( ESXi 5.0 ) with attached P4000/iSCSI SAN with basically 2 volumes configured. One is RAID-10 and the other RAID-5 single parity.

We recently moved a SQL app from bare metal ( Dell 2900/Windows 2003/RAID 0+1 or RAID10, not sure which) to a W2003 VM using the RAID-5 device as storage for the SQL DB. We have been getting some "feedback" that there is a perf issue with some of the batch jobs. The answer I'm sure is obvious, move them to RAID-10. However what, if anything, can be done to perhaps improve the RAID-5 performance?

I have seen some articles recommending cached I/O vs Direct, as well as setting the read/write cache to 30-70 or even 20-80. Is this possible on a P4000? If so, where? Additionally, I have seen a recommendation to disable read cache on the LUN itself?!

My suspicion is that there is little that can be done to tune the RAID-5 set further and that the perf hit is simply the nature of the beast.

Any/all feedback and input is greatly appreciated.

Thanks in advance.

BuddyD

P.S. This thread has been moved from Storage > General to HP StoreVirtual Storage / LeftHand.
-HP Forum Moderator

Re: P4000 noob questions

HPstorageTom — Thu, 26 Sep 2013 07:20:37 GMT

You better move the SQLDB from the Network-RAID 5 to a Network RAID 10 volume.

HP recommends to use Network-RAID 5 only for archive type of data.

Re: P4000 noob questions

oikjn — Thu, 26 Sep 2013 17:09:05 GMT

in addition... how many P4000 nodes do you have? Unless you have MANY, you really won't get much increase in space between NR10 and NR5 and the performance impact from NR5 is huge so other than increquently used static archives you really want to stick with NR10.

Re: P4000 noob questions

BuddyD — Tue, 29 Oct 2013 15:14:58 GMT

Thanks very much, yes I agree the issue is most likely R5.