Subject: SAS Drivers
From: roland <[email-masked]>
To: [email-masked]
Date: Thu, 23 Nov 2006 00:11:28 +0100

Hi Rick,

regarding http://linuxmafia.com/faq/Hardware/sas.html

>HP Smart Array 6x and 5x Series plus P600, P400, P400i, E200, E200i,6400,6400EM
>(and no doubt other) HBAs: Compaq cciss driver. Note that some other(non-SAS?)
>Smart Array cards use the mptlinux driver set, being based on MPT Fusion
>chipsets; there may be some SAS variants based on that chip family.

Yes, for example HP LSI 3041E (PCI-Express) or 3041X  (PCI-X)

regards
Roland Kletzing
System Engineer

Date: Wed, 02 Aug 2006 12:59:49 -0500
From: "Mr. Berkley Shands" <[email-masked]>
To: Rick Moen <[email-masked]>
Subject: lsi 8408e SAS fix

I stumbled upon a fix for the lsi8408e SAS controller and high write
rates:

Turn off read ahead in hardware. :-)

I lose 300MB/Sec in performance, but not having to powerfail machines to
clear hangs makes quite a difference :-)

LSI agrees there is a problem, they have given me 3 sets of BIOS for the
cards and two new drivers. But just disabling read ahead did the trick.
758MB/Sec write down to 581MB/Sec, and 780MB/Sec to 820MB/Sec on the
reads.

berkley

Date: Fri, 18 Aug 2006 08:55:06 -0500
From: "Mr. Berkley Shands" <[email-masked]>
To: Rick Moen <[email-masked]>
Subject: lsi 8408E fix

The best fix (you can update your sas web page now) is under 2.6.17 or
2.6.18 to re-enable cache, set write through, and disable read ahead in
hardware. Use 128KB stripe size. There is a bug in the supermicro
h8dc8/lsi8408e interaction. The bug is not seen on tyan motherboards.
Write performance of up to 700MB/Sec and read performance back up
1.1GB/sec with 7200.10 seagates. Older sata-2 drives yield slower
numbers.  the command line utility MegaCli has more functionality than
the GUI, but the GUI is better for creating the raid devices.

berkley

--

E. F. Berkley Shands, MSc