[2477] in linux-scsi channel archive
Re: SCSI Tape driver
daemon@ATHENA.MIT.EDU (Richard B. Johnson)
Wed Sep 17 10:52:05 1997
Date: Wed, 17 Sep 1997 09:06:08 -0400 (EDT)
From: "Richard B. Johnson" <root@chaos.analogic.com>
Reply-To: root@chaos.analogic.com
To: Kai.Makisara@metla.fi
cc: Linux scsi <linux-scsi@vger.rutgers.edu>
In-Reply-To: <Pine.OSF.3.96.970916231303.26112B-100000@abies.metla.fi>
On Tue, 16 Sep 1997, Kai M{kisara wrote:
> I think this discussion should be moved to linux-scsi.
I'm not on that list, but this c.c. will go there.
>
> On Mon, 15 Sep 1997, Richard B. Johnson wrote:
>
[SNIPPED]
> > File number=0, block number=0, partition=0.
> > Tape block size 512 bytes. Density code 0x45 (unknown).
> ^^^^
> What drive does this density belong to?
It's a Seagate Tape.Store 8000 so-called. Actually a CONNER CTT8000-S.
It uses Travan tapes QIC-3095, real garbage. Tape must be FORMATTED
and they "lose" their format after being written a few times. The
tapes are US$45 also! A real rip-off. There is no way to "reformat"
the tapes either.
>
> > Soft error count since last status=0
> > General status bits on (41010000):
> > BOT ONLINE IM_REP_EN
> > # ! Cleaned drive, inserted brand-new tape.
> > # cp /dev/zero /dev/st0 ! Instantly fails without even attempting to
> > cp: /dev/st0: I/O error ! access the physical device.
> > cp: /dev/st0: I/O error
>
> I have tried to recreate this problem in my system. I don't have a broken
> tape but I modified the mid-level scsi_done function to turn EOM into
> Medium Error. In my system (Adaptec AHA2940, HP C1533) the errors don't
> persist. After re-inserting the tape, I can rewrite it without problems.
> ...
> > It appears as though the driver "remembers" that there was a previous
> > command-completion failure and refuses to attempt the command again.
> > Actually, it's not the driver that remembers, it's the controller. The
> ^^^^^^^^^^^^^^
> or the drive
Maybe, but the access LED does not some on after such a fatal error.
> > driver seems to get sense data before each command rather than after,
> > and refuses to execute the new command because of bad sense data. This bad
> > sense data was from a previous command.
> >
> > Sep 15 10:10:32 chaos kernel: st0: Error with sense data:
> > Current error st09:00: sns = f0 3
> ...
> > Sep 15 10:10:32 chaos kernel: st0: Error with sense data:
> > Current error st09:00: sns = f0 3
> ...
> Getting twe same medium error twice is what I expect to happen if the
> drive finds a medium error: the driver tries to write the closing filemark
> after the error and this probably also fails.
>
This could very well be the case.
Cheers,
DJ
Richard B. Johnson
Analogic Corporation
Penguin : Linux version 2.1.54 on an i586 machine (66.15 BogoMips).
Warning : It's hard to stay on the trailing edge of technology.
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