Date: Fri, 12 Mar 1999 17:08:35 -0700 (MST) From: "Kenneth D. Merry" <ken@plutotech.com> To: cc@137.org (Chris Csanady) Cc: darrylo@sr.hp.com, freebsd-scsi@FreeBSD.ORG Subject: Re: SCSI disk oddities and Buslogic problems.. Message-ID: <199903130008.RAA34792@panzer.plutotech.com> In-Reply-To: <19990312235108.302BFAB@friley-185-205.res.iastate.edu> from Chris Csanady at "Mar 12, 1999 5:51: 8 pm"
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Chris Csanady wrote... > > Well, therein lies the problem. When I disable disconnection on these drives, > the performance is just as advertised. So, does it mean that the problem > is likely driver related? No, it doesn't. Try disabling tagged queueing for that disk and see what happens. (set the DQue bit on mode page 10 to 1 and reboot) Disabling disconnection effectively disables tagged queueing, I think. It means that the disk stays on the bus until a transaction is complete. It also means that no other disk will be able to get on the bus at the same time. I'm still confounded that you're having performance problems with that drive, when I've got > 100 of them and they perform just fine with tagged queueing and disconnection turned on. I would say that it's possible that you've got a bad firmware rev, but Steinar Haug has the same firmware rev, and gets good performance. It might also be worth running those disks on an Ultra-2 bus. Steinar Haug's disk is on an LVD bus. [long shot] It could be that the differential firmware for that drive has trouble running on a single ended bus. (All of the drives I have are single ended.) Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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