From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out.tiscali.be (spoolo1.tiscali.be [62.235.13.210]) by dsl2.external.hp.com (Postfix) with ESMTP id EE2A44914 for ; Sun, 22 Feb 2004 08:29:50 -0700 (MST) Message-ID: <4038CB15.5060507@tiscali.be> Date: Sun, 22 Feb 2004 15:30:29 +0000 From: Joel Soete MIME-Version: 1.0 To: Riccardo Subject: Re: [parisc-linux] Hanging with kernels >= 2.4.22 References: <20040218235225.GA1623@calypso> <20040219062907.GC13916@colo.lackof.org> <20040221075849.GA1642@calypso> <20040221170508.GB14198@baldric.uwo.ca> <4038C0B0.F7D1708A@tiscalinet.it> In-Reply-To: <4038C0B0.F7D1708A@tiscalinet.it> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Carlos O'Donell , parisc-linux@lists.parisc-linux.org List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Riccardo wrote: > Carlos O'Donell wrote: > >>>Thanks! Changing NCR_700_MAX_TAGS to 1 in drivers/scsi/53c700.h did the >>>trick. Will I now have poor disk performance? If so, might I get away >>>with setting it to something higher, like 2 or 4, maybe? >> >>I could never run IO stably at anything higher than 1. The drives don't >>seem to handle it properly, the error recovery mechanisms seem less >>than perfect, and the box just hangs. > > It really depends on the drive. I have a Fujitsu Enterprise and it has a > specified tag queue of 128 commands. So if something fails, it is the > driver or HP's hardware. > > I have a 715 scorpio and when I used ext2 or reiser with a tag queue of > 16 I had very frequent freezes up to a point were the system wouldn't > even mount the partition. > > There was a discussion that hp set it to 2 for workstations and to 8 for > servers. I have set it right now to 8 (since mavbe the NCR 7100 I have > doesn't even support more) and I use XFS instead of reiser. I had no > more problems... > > I would set the tag queue as default to 8 and not to 16, to stay on the > safe side. Couldn't it be made configurable from the kernel > configuration menu? > Good idea. > > What I notivced that some drives seem to be incompatible. I had 2 hard > disks that worked together (an original quantum divre rebranded HP and > an IBM disk). Since my ibm disk died I substitued it with the Fujitsu, > used a new Filesystem and a newer kernel. There was no way to see both > disks when linux booted. And you are sure that scsi id are well different and scsi chain well terminated, I supose. > I had to remove the original HP disk and > substitute it (a nuisance, since it contained the home directories). > Attaching each time only one of the two disks recognized the correct > disk respectively but both disk weren't. Another disk had no problem. > hmm, I leaved the same experience but with two external disks of exactly the same type (same supplier: hp, same manufactor: seagate, same product reference) but with a small firmware revision difference. Unfortunately, this pb only occured under linux :(. Now the disk is broken again; so no chance to test it with more recent kernel 2.4 or 2.6 :( Joel