PE 1800 PERC4/SC write performance

Matthew DeJong mdejong at dejonginc.com
Fri Apr 28 20:06:13 CDT 2006


Irwan, can you give more details about your configuration on the PE 1850
with Perc 4e/Si? I am interested in anything from the typical
installation of RHEL 4 that you turned off purposefully did not include.
Which drivers you are using. Also, Bios settings for the Perc controller
and if you made any particular tweaks. I have been reading a lot about
low/poor write performance on the Perc 4 series cards on RHEL 3 & 4, and
yours is the first setup that I have come across on the list that shows
a more acceptable RW speed.  

I have 3 PE 2850's with PERC 4e/DI RAID 1 with 2 73 GB 10k rpm drives
and dual 3.0 GHz Zeon processor (32bit).  Probably not pertinent, but I
also have Adaptec 39160 cards in each.  I am running RHEL 4 U 2 and my
write performance needs to be improved.  Here is an example Bonnie
output which tends to be very similar for 100MB, 500MB, 1GB:

              -------Sequential Output-------- ---Sequential Input--
--Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
          200 39086 97.4 218117 75.5 541264 94.3 46675 98.8 1883426 97.5
85235.1 161.9

This performance is happening whether or not the boxes are under load.
I am new to linux so hopefully I can provide similar information to what
I have been seeing.  I have been playing with the installation of Dell
megaraid drivers and testing difference Bios versions as well, so here
some information that might help.

Kernel: 2.6.9-22.ELsmp

Box 1 & 2
megaraid cmm: 2.20.2.5 (Release Date: Fri Jan 21 00:01:03 EST 2005)
megaraid: 2.20.4.4 (Release Date: Thu Jan 27 00:01:03 EST 2005)
megaraid: fw version:[521S] bios version:[H430]
megaraid: probe new device 0x1028:0x0013:0x1028:0x016d: bus 2:slot
14:func 0

Box 3
megaraid cmm: 2.20.2.5 (Release Date: Fri Jan 21 00:01:03 EST 2005)
megaraid cmm: 2.20.2.6 (Release Date: Mon Mar 7 00:01:03 EST 2005)
megaraid: 2.20.4.4 (Release Date: Thu Jan 27 00:01:03 EST 2005)
megaraid: 2.20.4.6 (Release Date: Mon Mar 07 12:27:22 EST 2005)
megaraid: fw version:[521X] bios version:[H430]

Thanks in advance for your help.

Matt DeJong



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