From owner-aic7xxx Thu Jul 27 13:22:43 2000 Delivered-To: aic7xxx@freebsd.org Received: from sapphire.fnal.gov (sapphire.fnal.gov [131.225.81.94]) by hub.freebsd.org (Postfix) with ESMTP id F04F637C0D0 for ; Thu, 27 Jul 2000 13:22:39 -0700 (PDT) (envelope-from timm@fnal.gov) Received: from localhost (timm@localhost) by sapphire.fnal.gov (8.9.3/8.9.3) with ESMTP id PAA06189 for ; Thu, 27 Jul 2000 15:22:39 -0500 X-Authentication-Warning: sapphire.fnal.gov: timm owned process doing -bs Date: Thu, 27 Jul 2000 15:22:38 -0500 (CDT) From: Steven Timm To: aic7xxx@freebsd.org Subject: re: Ultra160 SCSI vs. Linux Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-aic7xxx@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Last week I posted a query wondering if anyone has made an Adaptec AIC-7899 Ultra 160-SCSI adapter work under Linux. I received one response saying that maybe it was an issue with the SMP kernel. I tried. It wasn't. Same problems SMP or no. I have now tried versions of the kernel from 2.2.13 through 2.2.16-4, smp and not, under both RH 6.1 and 6.2. The peak write performance I get out of the drives is a bit under 10 Mb/sec. They should be good for twice that. Read speeds are usually, but not always fine. A couple interesting symptoms which may mean something to you guys: 1) Old kernels do better than new... 2.2.16-x kernels are only getting 2-4 Mb/sec write, as opposed to some of the red hat OEM kernels in 2.2.13 and 2.2.14 land that get close to 10. They have older versions of the aic7xxx driver--as old as 5.1.22 and 5.1.23, as opposed to the 5.1.30 available in the current kernels. 2) Disk 1 does better than disk 2...the farther down the SCSI bus the worse the performance gets. Could we be dealing with a termination problem here? Is there some SCSI bus diagnostic software available that can run under Linux similar to scu for Compaq tru-64? Any help is appreciated., Steve ------------------------------------------------------------------ Steven C. Timm (630) 840-8525 timm@fnal.gov http://home.fnal.gov/~timm/ Fermilab Computing Division/Operating Systems Support Central Systems Support Group--Computing Farms Operations To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message