[2556] in linux-scsi channel archive
Re: linux dump reading on Solaris
daemon@ATHENA.MIT.EDU (Dave Wreski)
Tue Sep 30 00:54:36 1997
Date: Mon, 29 Sep 1997 23:20:22 -0400 (EDT)
From: Dave Wreski <dave@nic.com>
To: Grant Beattie <gb@aus.ml.org>, Sven Dummer <sdummer@gwdg.de>
cc: linux-scsi@vger.rutgers.edu, linux-admin <linux-admin@vger.rutgers.edu>
In-Reply-To: <199709300056.KAA11296@home.mariah.net.au>
Hmm. It appears two different users on two different lists are having the
same problem. Possibly we can kill two birds with one stone :)
On Tue, 30 Sep 1997, Grant Beattie wrote:
> I would like to read the tape on Solaris, but I don't seem to be having
> much success. ufsrestore has been segfaulting etc, regardless of what
> block size I try.
Directly from the SCSI-HOWTO:
8.2.4. Problems taking tapes to/from other systems
You can't read a tape made with another operating system or another
operating system can't read a tape written in Linux.
Different systems often use different block sizes. On a tape device
using a fixed blocksize, you will get errors when reading blocks
written using a different block size.
To read these tapes, you must set the blocksize of the tape driver to
match the blocksize used when the tape was written, or to variable.
NOTE : this is the hardware block size, not the blocking factor used
with tar, dump, etc.
You can do this with the mt command -
mt setblk <size>
or
mt setblk 0
to get variable block length support.
Note that these mt flags are NOT supported under the GNU version of mt
which is included with some Linux distributions. Instead, you must
use the BSD derived Linux SCSI mt command. Source should be available
from
tsx-11.mit.edu:/pub/linux/ALPHA/scsi
Also note that by default, ST_BUFFER_BLOCKS (defined in
/usr/src/linux/drivers/scsi/st_options.h in newer kernels, st.c in
older kernels) is set to allow for a 32K maximum buffer size; you'll
need to edit the source to use larger blocks.
I guess this may not help your current situation with trying to read
existing data on a tape on another OS, but at least you should be able to
write data from now on, and read it on another OS..
Dave
