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From: grog@lemis.de (Greg Lehey)
Organisation: LEMIS, Schellnhausen 2, 36325 Feldatal, Germany
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	id OAA13325; Sun, 22 Sep 1996 14:39:29 +0200
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Subject: Re: TANDBERG TDC3600 - need multiple 512
To: roberte@mep.ruhr-uni-bochum.de (Robert Eckardt)
Date: Sun, 22 Sep 1996 14:39:29 +0200 (MET DST)
Cc: questions@FreeBSD.org (FreeBSD Questions)
In-Reply-To: <199609221236.OAA00963@ghost.mep.ruhr-uni-bochum.de> from "Robert Eckardt" at Sep 22, 96 02:36:45 pm
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Robert Eckardt writes:
>
>> TITO writes:
>>>
>>>
>>> I've a problem with make a tar backup to streamer TANDBERG.
>>>
>>>
>>> When I use the option z ( to make tar with gzip ), the system returns this
>>> bug.
>>>
>>> 	input/output error - must be multiple 512
>>
>> Interesting one.  First, what it means: the driver wants a write
>> length which is a multiple of 512 bytes.  That works well enough with
>> tar normally, but not if you compress, in which case it writes in
>> dribs and drabs.  You can fix it with:
>>
>> tar czf - <files> | dd obs=20b of=/dev/rst0
>>
>> This will force a block size of 20 blocks.
>
> Or you could use (from tar --help):
> --block-compress        block the output of compression program for tapes
>
> Therefore, 'tar -czf /dev/rst0 --block-compress <files>' works (for me)
> (except that compression on my 486 stops the tape from streaming :-)

Thanks.  That's obviously a better choice.

Greg