From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from colo.lackof.org (colo.lackof.org [198.49.126.79]) by dsl2.external.hp.com (Postfix) with ESMTP id 2BB924868 for ; Wed, 7 Jan 2004 19:52:20 -0700 (MST) Date: Wed, 7 Jan 2004 19:52:18 -0700 From: Grant Grundler To: Steve Bromwich Subject: Re: [parisc-linux] scsi problem on a scorpio (715) Message-ID: <20040108025218.GA20732@colo.lackof.org> References: <3FFC9A15.6FA66B2@tiscalinet.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: Riccardo , parisc linux List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jan 07, 2004 at 10:30:30PM -0400, Steve Bromwich wrote: > Grant Grundler mentioned that "as of 5 years > ago, HP-UX default was 8 for servers and 2 for workstations"; The drives shipped with workstations had "Write Cache Enable" (aka WCE) turned on by default. Not good if you really care about your data. But Tag queue depth of 2 works great because the drive will immediately report "success" until it's on-board cache was full. > as the 715 > is a workstation it might be worth trying setting tags to 2 and seeing > what happens? Unless performance is more important than strict correctness, I still reccommend tag queue depth of 8 and disable "Write Cache" setting. Reducing queue depth further typically only limits performance. I suspect something else is wrong in Riccardo's case. But it wouldn't hurt disable queue tags completely and see if that is at least stable. root@debian:~# sginfo -c /dev/sda Data from Caching Page ---------------------- Write Cache 0 Read Cache 1 Prefetch units 0 Demand Read Retention Priority 0 Demand Write Retention Priority 0 Disable Pre-fetch Transfer Length 65535 Minimum Pre-fetch 0 Maximum Pre-fetch 65535 Maximum Pre-fetch Ceiling 65535 hth, grant