Subject: Re: misunderstood SCSI failure with Adaptec 2842VL controller
To: None <firstname.lastname@example.org>
From: der Mouse <mouse@Holo.Rodents.Montreal.QC.CA>
Date: 11/27/1996 13:46:00
> I have an Archive 150 tape drive talking to an Adaptec 2842VL
> controller. Tar seems to write the tape o.k. until it wants to close
> the device. I get:
> tar (child): can't write to /dev/rst0 : Input/output error
> And in messages I get:
> Nov 24 10:08:19 dakkon /netbsd: st0: bad request, must be multiple of 512
> What does this mean???
It means tar tried a write() operation with a size that is not a
multiple of 512, as the kernel message says. QIC tapes do not fit the
traditional UNIX tape model of streams of records with filemarks (with
some record size limits, usually 0<=size<=63k or some such); instead,
they are streams of 512-byte blocks with filemarks.
Why this is happening is another story. What tar command line are you
using? A tar archive is always a multiple of 512 bytes long, so either
there's a critical bug in tar or something else is happening - I think
NetBSD uses GNU tar; are you using the z option, which causes tar to
gzip the archive? I suspect tar doesn't pad and reblock the gzipped
output if you do that (which is arguably a, bug but that's neither here
nor there at the moment).
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