P2000 G3 iSCSI - very slow read performance

[Chris_Ciapala]

Hi all,

I have 2x P2000 G3 iSCSI, each with 12 SAS 10k hdds, connected via dedicated switch to 3x DL380 Gen8. Array firmware is the latest publicly available, servers also with latest PSP.

The problem: sequentials writes are close to the max, around 500 MB/sec, but sequential reads are max 120MB/sec. 

Additionally while writes are stable (looking at network and P2000 stats), reads are jumping all the time, both in MB/sec and IOPS. I know it is a clue, but I don't know to what. At this moment I have 2xRAID10s, each sitting on own controller, which are stripped with LVM on Centos 7. That gives best write rate, but reads still are low.

I've tested both arrays, with vmware 5.5 (which is planned to be there), bare-metal Windows 2012 and bare-metal Centos 7 and 6.6. I also tried direct network connection, to exclude switch issues.

To be honest I'm out of ideas, there is not much what can be done/set on the array itself. Surely the read performance should be much higher?

thanks for any thoughts,

Chris

[Hermanbrood]

I have the exact same issue. Write speeds are very good (400 MB/s+), read speeds are limited to 120 MB/sec or so. The configuration of my MSA P2000 G3 (iSCSI) is:

16 X 10K 600 GB in a RAID50 volume (2X8)

Multipath I/O policy = Round robin with subset

OS = Windows 2012 R2 Datacenter