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From: Wilko Bulte <wilko@yedi.iaf.nl>
Message-Id: <199704211840.UAA00759@yedi.iaf.nl>
Subject: Re: Vendor specific ASCQ SCSI errors in 2.2-STABLE
To: gibbs@plutotech.com (Justin T. Gibbs)
Date: Mon, 21 Apr 1997 20:40:54 +0200 (MET DST)
Cc: Alan.Judge@indigo.ie, freebsd-scsi@freebsd.org
In-Reply-To: <199704211520.JAA09950@pluto.plutotech.com> from "Justin T. Gibbs" at Apr 21, 97 09:19:08 am
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As Justin T. Gibbs wrote...
> >I sometimes get errors of the form:
> >        sd0(ahc0:0:0): ABORTED COMMAND asc:41,86 Vendor Specific ASCQ, retries
> >:4
> >only under high load and on multiple different disks (as far as I can reproduc
> >e
> >the problem).
> 
> >From a quick look at the Atlas II tech ref I have here, this is:
> 
> DDMA overrun or REQ/ACK overrun/underrun error.

This could well be a glitch on the REQ/ACK lines. Having bus stubs 
(inside the canisters) makes the drives vulnerable to this problem.

Any chance you can try things without the canisters? (I know,
a horrible lot of work). An active terminator on the end of the
bus instead of a drive-internal terminator in a canister is also
worthwile.

Wilko
_     ____________________________________________________________________
 |   / o / /  _  Bulte  email: wilko@yedi.iaf.nl - Arnhem, The Netherlands
 |/|/ / / /( (_) 	Do, or do not. There is no 'try' - Yoda
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