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To: se@MI.Uni-Koeln.DE (Stefan Esser)
cc: Doug Rabson <dfr@render.com>, current@FreeBSD.org
Subject: Re: DAT tape problems 
In-reply-to: Your message of "Tue, 18 Apr 1995 19:10:29 +0200."
             <199504181710.AA17946@FileServ1.MI.Uni-Koeln.DE> 
Date: Tue, 18 Apr 1995 12:39:08 -0700
From: "Justin T. Gibbs" <gibbs@estienne.CS.Berkeley.EDU>
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>On Apr 18, 14:19, Doug Rabson wrote:
>} Subject: DAT tape problems
>} I just attempted to read back a dump from a DAT tape to test our backup 
>} strategy and disturbingly, the file which read back from the tape was 
>} corrupted.  The directory was intact but when the dump was extracted, 
>} there was a checksum error on one file and when comparing the extracted 
>} tree with the original, at least one file had been corrupted.
>} 
>} My DAT drive probes as a 'WangDAT Model 3400DX' and it is set to use 
>} compression.  Does anyone have an idea what is happening?
>
>DAT drives are supposed to work !
>
>I'm using a HP 1533 DDS-2 drive with good success.
>
>What controller are you using ?
>
>There is special code in the NCR driver, that deals 
>with certain DAT drives, which don't accept SCSI
>messages within an GETCC command. In case you are
>using this controller, your particular drive ID 
>might need to be entered in some table in the driver.
>
>Most other controllers ought to deal with this in 
>the controller firmware.
>
>Regards, STefan
>-- 
> Stefan Esser				Internet:	<se@ZPR.Uni-Koeln.DE>
> Zentrum fuer Paralleles Rechnen	Tel:		+49 221 4706019
> Universitaet zu Koeln			FAX:		+49 221 4705160
> Weyertal 80
> 50931 Koeln

Can we better publicize these "known rogue" devices.  I hadn't heard of
this problem, so if it needs controller firmware mods, I'd like to know
about it.

Do these problems have to be handled at the controller level? or can they
be handled more generically?
--
Justin T. Gibbs
==============================================
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