From: roland To: rick@linuxmafia.com Date: Thu, 23 Nov 2006 00:11:28 +0100 X-Mailer: Microsoft Outlook Express 6.00.2900.2869 Subject: SAS Drivers 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" To: Rick Moen 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" To: Rick Moen 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