Date: Tue, 29 Aug 2000 09:14:36 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: David Gilbert <dgilbert@velocet.ca> Cc: freebsd-SCSI@FreeBSD.ORG Subject: Re: SCSI disconnect with quantum Atlas IV disks. Message-ID: <20000829091436.A38504@panzer.kdm.org> In-Reply-To: <14763.53851.632330.327801@trooper.velocet.net>; from dgilbert@velocet.ca on Tue, Aug 29, 2000 at 11:10:19AM -0400 References: <14762.31347.647187.677745@trooper.velocet.net> <20000828233257.A35815@panzer.kdm.org> <14763.53851.632330.327801@trooper.velocet.net>
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On Tue, Aug 29, 2000 at 11:10:19 -0400, David Gilbert wrote: > >>>>> "Kenneth" == Kenneth D Merry <ken@kdm.org> writes: > > Kenneth> I kinda wonder if your enclosure is underpowered. One thing > Kenneth> that can cause drives to behave strangely is if they aren't > Kenneth> getting enough power. > > Kenneth> When drives spin up, and when they're under high seek load, > Kenneth> they use a fair bit more power than they do when they're just > Kenneth> spinning idle. > > Kenneth> Are your drives alone on that power supply? If so, you > Kenneth> should be able to look at the drive specs for peak > Kenneth> current/power usage, and compare that with what your power > Kenneth> supply is spec'ed for. > > The case is designed for 8 drives. There are two (redundant) power > supplies and there are 8 drive power connectors supplied (along with > two motherboard connectors that are unused). These are 18G Atlas IV's > which are 7200 RPM drives (not even the fastest out there). Just to be sure, you should check the power rating on one of the power supplies against the peak power usage for the drives. (Quantum should have specs on their web site somewhere.) > Kenneth> The types of errors you're getting, timed out in data-out > Kenneth> phase, indicate that a signal is stuck on the SCSI bus. It's > Kenneth> not just stuck momentarily, but has been stuck for 60 > Kenneth> seconds. > > Kenneth> I suppose that could be caused by power problems, although it > Kenneth> is more often a cabling and termination problem. > > Well... The cables are the ones that come with the TekRAM 390F. > They're twisted in a funny way and they have 6 connectors (4 drives, > card and terminator). The terminator is physically in the last > connector and the controller is in the first. LVD cables have been known to show up with bent or loose pins, which could certainly cause problems. Sometimes they're a little more fragile than normal Ultra-Wide or narrow SCSI cables. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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