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From: jgd@rsiatl.UUCP (John G. DeArmond)
Newsgroups: comp.periphs.scsi
Subject: Re: SCSI error -- medium changed in drive
Keywords: SCSI reset error media changed
Message-ID: <5131@rsiatl.UUCP>
Date: 27 Nov 90 22:27:46 GMT
References: <66.UUL1.3#1@vortex.COM> <1604@travis.csd.harris.com>
Organization: Rapid Deployment Systems, Inc. (making go fast things and things go fast)
Lines: 35

garyb@SSD.CSD.HARRIS.COM (Gary Barton) writes:

>In article <66.UUL1.3#1@vortex.COM> lauren@vortex.COM (Lauren Weinstein) writes:

>>*** DEVICE ERROR: Medium has been changed in drive ***

>Most CCS disk drives use the same additional sense code to indicate a
>device was reset or the media may have changed.  I suspect that
>something caused the SCSI bus to be reset, which then generates a
>check condition with this error code on the next access.  SCSI device
>drivers generally expect to see this condition after they have forced
>a device or bus reset, but if it occurs outside of their control, they
>treat it like any other error.  It could be that device/bus reset was
>attempted as part of some error recovery procedure by the disk (or
>other) driver.  


I think this is pretty much correct in the case of ISC's handler.  I've
seen that message here in the context of something really gross happening
to the SCSI bus - cable working loose or a radio being keyed too
close to the cable or a lightening strike nearby or a drive giving it
the last dying quiver :-(

Unless it repeats, I'd write it off to cosmic causes.  When I had a
drive dying, I saw that a lot.  About the only recourse is to pull
the plug and let Mr. fsck cleanup the carnage.  The ISC driver just
says "to hell with it, I'm leaving" and that's that.

John

-- 
John De Armond, WD4OQC        | "Purveyors of speed to the Trade"  (tm)
Rapid Deployment System, Inc. |  Home of the Nidgets (tm)
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