From owner-aic7xxx Tue Mar 12 15: 7:35 2002 Delivered-To: aic7xxx@freebsd.org Received: from scotty.rfa.org (scotty.rfa.org [207.123.167.15]) by hub.freebsd.org (Postfix) with ESMTP id DDDAE37B42C for ; Tue, 12 Mar 2002 15:07:17 -0800 (PST) Received: from rfa.org (peter.rfa.org [207.123.167.16]) by scotty.rfa.org (8.11.6/8.11.6) with ESMTP id g2CN7Gd14397; Tue, 12 Mar 2002 18:07:16 -0500 Message-ID: <3C8E8A24.30EB6920@rfa.org> Date: Tue, 12 Mar 2002 18:07:16 -0500 From: Eric Dantan Rzewnicki Organization: Radio Free Asia - NIS X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.2-0 i686) X-Accept-Language: en MIME-Version: 1.0 To: "Justin T. Gibbs" Cc: aic7xxx@FreeBSD.ORG Subject: Re: performance issues: linux aic7xxx, 29160, Radion IFT-7200 References: <200203122221.g2CMLSI34053@aslan.scsiguy.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-aic7xxx@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org "Justin T. Gibbs" wrote: > > >Hello again, > > I wonder if for some reason we have disconnection disabled? I get much > better performance than that talking to a plain old 10K RPM disk. Can > you go into aic7xxx.c, search for ahc->user_discenable and print out the > contents of that variable? linux-2.4.18/drivers/scsi/aic7xxx/aic7xxx.c (not-patched, so this is version 6.2.4) line 4547 ahc->user_discenable = discenable; same in 2.4.16 ( I guess that's the same version so that would make sense, of course...) after patching the 2.4.18 sources for aic7xxx 6.2.5 the file names in drivers/scsi/aic7xxx/ are different. Which one should I be looking at there? > > Both drivers negotiate to the same values? yes, with both 5.2.4 and 6.2.4 the raid and the system disk negotiate to 160.0MB/s > > >Is there something else I can do to try to get better performance with > >the new driver? > > If I understood why the performance was bad, I'd tell you. 8-) > Any chance you can rent a SCSI bus analyzer for a day and capture > some traces? umm, I'll check with the boss, but I doubt it. Where would a person rent such a thing? > > >You made a distinction between sequential and non-sequential workloads. > > If you have multple mp3's being written or read from at the same time, > this will be a non-sequential workload. If you are only doing one > at a time, it will be a sequential workload. Ok, so probably very few people would ever care only about sequential performance? We will have up to 4 streams of current broadcasts writing to disk and potentially 'many' users streaming via http or copying via http or smb from the archive. And for a time, someone will be copying the past archives off CDs onto the raid via a samba share. Can hdparm be used to measure non-sequential performance? is there a way to quantify this? > > -- > Justin -Eric To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message