Subject: Re: MI tape problem
To: None <daniel@bicho.synchrodesign.com>
From: maximum entropy <entropy@tappedin.com>
List: port-pmax
Date: 01/26/2003 17:31:43
Daniel Senderowicz said:
> Your command worked (it should say 'setblk' instead of 'stblk').

Yes, sorry about the typo.

> These tapes have been generated with a simple tar command, e.g.
>
> tar cv ...
>
> so they are supposed to be 512-byte fixed blocks, right?
> Sometimes the console message is (instead of 20 blocks residual):
>
> st0: block wrong size, 4 blocks residual
> st0(xasc0:5:0): Sense Key 0x05, data = 07 00 00 00 00 00
>
> I made an experiment to reboot the system with 1.4.2 and the tape
> can be read with 'tar' without problems. Could be something
> related to the MI scsi interface?

It's possible that the newer drivers default to fixed-512 blocks and the
older ones defaulted to variable blocks.  I don't know if this is a bug or
a feature.

You could try booting 1.4.2 and see what "mt -f /dev/nrst0 status" reports
for the block size.

You can set the block size used by GNU tar, with the -b flag.  It defaults
to 20 (* 512 = 10240).  You will still need to use "mt -f /dev/nrst0
setblk 0" first to enable variable-sized blocks.

Cheers,
entropy