Subject: Re: mt(1) doesn't report file number?
To: None <mjacob@feral.com>
From: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
List: port-sparc
Date: 03/21/2002 23:46:49
At 13:32 Uhr -0800 21.3.2002, Matthew Jacob wrote:
>On Thu, 21 Mar 2002, Hauke Fath wrote:
>> Tandberg SLR4, SLR5, SLR60. There are two distinct issues here for QIC
>> derived drives:
>>
>> o  support for variable block length (which all the SLR models do just
>> fine, and which st(4) does not even read for QIC)
>
>I really have problems with variable mode emulation in QIC drives. I really
>think it's a bad idea. I kow lots of people would disagree.

I know you know.  =8)

But, my experience is just the other way 'round. Therefore, I would like to
have at least the _option_ of variable block length, and currently st(4)
nails QIC drives on 1024 or even 512 Byte blocks which is not even
appropriate for any relevant (>= QIC 320) drive.

>> o  1FM@EOT vs. 2FM@EOT (which is relevant for writing more than one file on
>> a tape -- think 'Amanda')
>>
>> Matthew, if you are interested, I can send you the patches I use at work
>> (and will have to re-apply soon when I upgrade the machine's kernel).
>
>
>Amanda is broken in lots of interesting ways.

While that may be (I've yet to see it), the issue is not Amanda's fault:
You can see it with dump, tar or what-have-you the moment you try to append
to a QIC tape. IMHO, the problem is that the NetBSD st writes 2FM@EOT after
the nine track tape's habit, while QIC transparently writes 2FM for 1FM@EOT
(i.e., doubles the FM internally).

>Send patches if you like.

Will do.

>The NetBSD driver could probably use the level of effort I put into the
>FreeBSD driver- if not more.

Yep.

>But, folks, I have a very limited amount of time
>to spend on this these days (parenthood struck)- so don't expect *too* much.

I understand.

Actually, I've been collecting tape-related data sheets, links, mails, news
snippets for a long time, but I feel I am lacking expertise by far (not to
mention equipment).

	hauke


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