Welcome to the most active Linux Forum on the web.
Go Back > Forums > Linux Forums > Linux - Server
User Name
Linux - Server This forum is for the discussion of Linux Software used in a server related context.


  Search this Thread
Old 11-14-2010, 04:05 PM   #1
LQ Newbie
Registered: Nov 2010
Location: Germany, NRW
Distribution: Gentoo
Posts: 1

Rep: Reputation: 0
Throughput problem with MPT Fusion SAS

Hello Forum,

I've got the following setup:
  • LSI SAS1068E PCI-Express Fusion-MPT SAS
  • Hitachi Deskstar 7K1000.C (8x)
  • 4-core Xeon
  • some Intel server board
  • kernel 2.6.34 and 2.6.35 (tried both)

Fusion MPT base driver 3.04.15
Fusion MPT SAS Host driver 3.04.15
I've also tried the current driver from LSI themselves (v4.2.4, iirc).

Anyway, I'm not using any of the RAID capabilities of the controller but I am accessing the drives directly. I have a ZFS RAID-Z2 (dedup=on, compression=on) across all eight disks which shows a rather bad performance with small writes. And by bad, I mean this bad (measured using bonnie++):

Anyway, it's the same without dedup and compression and even the same when writing directly to the devices:

ltm-memorix ~ # dd if=/dev/zero of=/dev/sdb bs=1kB count=500000
500000+0 Datensätze ein
500000+0 Datensätze aus
500000000 Bytes (500 MB) kopiert, 26,0034 s, 19,2 MB/s
ltm-memorix ~ # dd if=/dev/zero of=/dev/sdb bs=5kB count=100000
100000+0 Datensätze ein
100000+0 Datensätze aus
500000000 Bytes (500 MB) kopiert, 21,2242 s, 23,6 MB/s
ltm-memorix ~ # dd if=/dev/zero of=/dev/sdb bs=10kB count=50000
50000+0 Datensätze ein
50000+0 Datensätze aus
500000000 Bytes (500 MB) kopiert, 12,7889 s, 39,1 MB/s
ltm-memorix ~ # dd if=/dev/zero of=/dev/sdb bs=20kB count=25000
25000+0 Datensätze ein
25000+0 Datensätze aus
500000000 Bytes (500 MB) kopiert, 8,44659 s, 59,2 MB/s
ltm-memorix ~ # dd if=/dev/zero of=/dev/sdb bs=1000kB count=500
500+0 Datensätze ein
500+0 Datensätze aus
500000000 Bytes (500 MB) kopiert, 6,91047 s, 72,4 MB/s
As you can see, write performance gets a lot better with bigger block sizes. What am I doing wrong here? On my desktop machine with its cheap SiL controller I'm getting WAY better throughput.
Old 11-14-2010, 04:26 PM   #2
Senior Member
Registered: Dec 2005
Location: Massachusetts, USA
Distribution: Ubuntu 10.04 and CentOS 5.5
Posts: 3,873

Rep: Reputation: 332Reputation: 332Reputation: 332Reputation: 332
Here's an idea from
Posted: Thu Nov 09, 2006 8:50 pm Post subject: Reply with quote
While googling around I came across this thread for a similar model xw9300

I turned ACPI Segmentation off in the bios and the sucker came right up. I haven't tried the pci=noacpi with ACPI Segmentation turned on but I image it would work if I needed ACPI Segmentation on. Thanks to bgregorcy for trying to help me as he was the only one. Hope this thread helps others with similar hardware.
May or may not be related. The above post was about the devices not showing up at all but still maybe playing with ACPI on the motherboard might help.

There is more food for thought at
so at the end I did what is recommended in the article provided by pschaff, I disabled the RAID on the motherboard (jumper setting) and moved the cables from the SAS ports to the normal SATA ports.

Last edited by stress_junkie; 11-14-2010 at 04:36 PM.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
MPT driver installation on Debian 4.0 to support HP SC44Ge SAS host bus adaptor fireball1974 Debian 12 06-01-2011 09:19 AM
Random boot kernel panic with MPT Fusion SCSI Artanicus Linux - Hardware 2 08-02-2010 02:03 PM
Slackware 13.0 Fusion MPT Kernel Panic ColdSQL Slackware 7 05-18-2010 05:16 PM
What's the difference between MPT fusion and original driver? PhillipHuang Linux - Software 0 12-11-2007 03:37 AM > Forums > Linux Forums > Linux - Server

All times are GMT -5. The time now is 12:39 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration