Date: Mon, 14 Dec 1998 10:53:10 -0700 (MST) From: "Kenneth D. Merry" <ken@plutotech.com> To: spork@super-g.com (spork) Cc: freebsd-scsi@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG Subject: Re: CAM and -stable Message-ID: <199812141753.KAA54713@panzer.plutotech.com> In-Reply-To: <Pine.BSF.4.00.9812141207050.6123-100000@super-g.inch.com> from spork at "Dec 14, 98 12:43:11 pm"
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spork wrote... > On Mon, 14 Dec 1998, Kenneth D. Merry wrote: > > > spork wrote... > > > > [ sorry for not responding to your previous message. I thought Justin > > would respond, but evidently he never got around to it. ] > > No problem, I was a little nervous, that's all... > > > Generally, it's a sign that the device has gone "out to lunch", and we have > > to whap it over the head with a BDR to get it to wake up. > > Are you aware of anyone else running a CMD controller? I know wcarchive > is using the Mylex box. I hope I've made a good choice... I believe Karl Denninger is using a CMD controller on one of his machines, with CAM. You'd have to ask him for details, though. > > You also have another problem, which wasn't evident in your earlier mail. > > The tagged openings on one of your RAID partitions have gone down to 2. > > That indicates that the device keeps sending queue full until we reduce the > > number of tagged openings to the lowest possible value (2). I would > > suggest looking in the CMD docs, and try to figure out if they say how many > > simultaneous transactions the device can handle. Take that number, divide > > it by 2 (you've got two partitions on the device), and make that the > > maximum number of tags in a quirk entry in the transport layer. Make the > > minimum number of tags something slightly less than that. > > How and where do I set the number of tags? The docs > (http://www.cmd.com/storage/products/docs/datasheet/crd5440.cfm) say that > the unit can queue 64 commands. There are two hosts on this controller in > our installation. I'm no scsi genius, are 'tags' and 'queued commands' > the same thing? Yes, they are. > > Generally, the system will recover all right from the 'timed out while > > idle' problem. After we hit the device with a BDR, all the CCBs that have > > already been sent to the device are aborted, and we requeue them all. > > Yep, it's only froze up completely once. Is your feeling that if I adjust > it to use less tags this should go away? I checked the CMD website, and > there is one more firmware update, but it doesn't address any serious > issues. It might very well go away. The only way to find out is to try it. Since it can supposedly handle 64 commands, you might try setting the maximum in the quirk entry to 32, to divide the load evenly. You could set the minimum to 24 or so. > And one last thing, will there ever be a newer patchkit for CAM under > stable? My timing is horrible, I need to put these machines in production > in the next week or so, so I can't really go to 3.x right now... In 6 > months or so, sure, but these will probably remain at 2.2 for quite some > time. Are there major changes from what I'm running in the 3.x tree? Yes, there will be a new -stable patchkit. At least that's been the plan. Justin makes the snapshots, and I'm not sure what his plans are. I can tell you, however, that unless it gets made this week (unlikely), it won't happen until January. 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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