Date: Fri, 15 Oct 1999 09:01:38 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: "Kenneth D. Merry" <ken@kdm.org>, scsi@FreeBSD.ORG Subject: Re: FreeBSD 3.2 / Slow SCSI Dell PowerEdge 4300 Message-ID: <Pine.BSF.4.05.9910150901250.6773-100000@semuta.feral.com> In-Reply-To: <14343.16009.738375.608477@grasshopper.cs.duke.edu>
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On Fri, 15 Oct 1999, Andrew Gallatin wrote: > > Geoff Buckingham writes: > > On Thu, Oct 14, 1999 at 04:55:45PM -0600, Kenneth D. Merry wrote: > > > > > > Western Digital drives generally aren't that great. In fact, we have > > > disabled tagged queueing for most all Western Digital SCSI drives. > > > (including the drives you have, above) > > > > > > > I have been meaning to post on this subject for some time, while in my last > > place of employment I bought 8 Dell PowerEdge 2300s each with six drives > > Dell supplied Western digitals and I had really poor disk performance. > > > > I realised tagged queing was disabled for WDE* and removed the quirk from > > cam_xpt.c this greatly improved the performance. Much exercising of the disks > > also failed to cause any further problems. > > I'm the guy to blame for this quirk. My drives (shipped in about 60 > older Dell Dimension XPS D300 here) have abysmal sequential write > performance with tagged queuing enabled. There are two types of > identifiers: > > pass0: <WDIGTL WDE4360-1807A3 1.80> Fixed Direct Access SCSI-2 device > pass0: Serial Number WS7010610507 > pass0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > > pass1: <WDIGTL ENTERPRISE 1.91> Fixed Direct Access SCSI-2 device > pass1: Serial Number WS7011244369 > pass1: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > > >From the reports I've seen, it looks like Western Digital got their > act together and their Ultra2 drives are OK. Could we make the quirk > entry enable tagged queuing for Ultra2 WDE drives & disable it for > non-ultra2 drives? > > Also, would it be possible to enable/disable tagged queuing from > camcontrol? Or to read the quirks from a config file (like Digital > UNIX does with its ddr.db file..). > This is on my list to address. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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