HP StorageWorks MSA Storage P2000 G3 iSCSI: very poor reading performance

[ciopsa]

Hello all,

we are experiencing quite poor reading performance (order of 15 Mb/sec !!!)  on all the volumes/vdisk we created on a  HP StorageWorks MSA Storage P2000 G3 iSCSI.

Here some details: 

The HW is composed by four chassis for a total of 48 disks.  

Disks are of two kinds:

12 600GB disk 15k RPM  ST3600057SS in the first enclosure 

36 2TB disks 7.2K RPM   ST32000444SS  in the 3 other enclosures.

The storage has two controller for a total of four 10gB isci port connected to a 10gigabit switch and then connected to four i/o Linux server (iosrv[1-4]).

The configuration we setup is attached here in the picture (as png file: hope it is ok) 

On the storage we created 5 different vdisks (one raid6 for the 600GB disks and 4 for the 2TB disks (raid 5 with  global spare).Here below the details: 

# show vdisks
Name Size Free Own Pref RAID Disks Spr Chk Status Jobs Serial Number Drive Spin Down Spin Down Delay
--------------------------------------------------------------------------------------------------------------------------------------------------------
vd01 5995.1GB 3522.5KB A A RAID6 12 0 64k FTOL 00c0ff1153d10000f74e844e00000000 Disabled 0
vd03 15.9TB 704.5KB B B RAID5 9 0 64k FTOL 00c0ff1154c50000c8815b4e00000000 Disabled 0
vd04 15.9TB 704.5KB B B RAID5 9 0 64k FTOL 00c0ff1154c5000042825b4e00000000 Disabled 0
vd05 15.9TB 704.5KB B B RAID5 9 0 64k FTOL 00c0ff1154c5000076825b4e00000000 Disabled 0
vd06 13.9TB 983.0KB B B RAID5 8 0 64k FTOL 00c0ff1154c5000073eb794e00000000 Disabled 0
-------------------------------------------------------------------------------------------------------------------------------------------------

On each vdisk we just created one single  volume:

# show volumes
Vdisk Name Size Serial Number WR Policy Cache Opt Read Ahead Size Type Class Qualifier Volume Description
------------------------------------------------------------------------------------------------------------------------------------------------------------------
vd01 fast1_iosrv2 5995.0GB 00c0ff1153d10000b64f844e01000000 write-back standard Default standard standard N/A
vd03 slow1_iosrv1 15.9TB 00c0ff1154c50000530c654e01000000 write-back standard Maximum standard standard N/A
vd04 slow1_iosrv2 15.9TB 00c0ff1154c50000e40d654e01000000 write-back standard Maximum standard standard N/A
vd05 slow1_iosrv3 15.9TB 00c0ff1154c50000e3db644e01000000 write-back standard Maximum standard standard N/A
vd06 slow1_iosrv4 13.9TB 00c0ff1154c50000e5ec794e01000000 write-back standard Default standard standard N/A
-------------------------------------------------------------------------------------------------------------------------------------------------

Writing on any of the volumes from I/O server we measured around 350Mb/secs that we consider satisfactory.

Reading from them we measured no more than 15Mb/sec !, no matter which combination of cache parameters we choose.

Measures were performed by  dd command  on 50giga files just to avoid cache problems on the i/o servers ( each of the them have 24GB ram).

Investigating the problem we discovered that firmware on the device is one year old:

# show versions

Controller A Versions
---------------------
Bundle Version: TS210R016
Build Date: Mon Aug 30 18:59:22 MDT 2010

Controller B Versions
---------------------
Bundle Version: TS210R016
Build Date: Mon Aug 30 18:59:22 MDT 2010

(even if the system was delivered in july 2011) and we plan to upgrade it.  

Yet we still  think we cannot just blame the old firmware for such a problem.

Is there anybody in the forum who can give us some insight  ?

Is there something dramatically wrong on our setup ? 

Please advice

thanks in advance !

Stefano&friends