--- Matt Herzog <mherzog@attbi.com> wrote:
> Hi All.
> 
> I just started playing with my new Seagate Hornet
> scsi tape drive.  The first
> time I loaded a tape and ran a dump, it seemed to be
> working fine but stopped
> and asked for another tape. My script failed to
> complete it's tasks, i.e.
> failed to mount the new tape, and gave some error I
> didn't think to save.
> There is no way this dump could have used up my 10GB
> tape because the NetBSD
> (1.5.2) slice of the disk is only 4GB.
> 
> Anyway, ever since this first usage I cannot talk to
> the device even with
> the simplest mt commands. All mt commands render the
> same i/o error message.
> 
> # mt status
> mt: /dev/nrst0: Input/output error

Not being a scsi or tape expert (at least not at the
workstation level), my experiece is limited. However,
whenever I receive the error on my own personal drive,
there is no tape in it. Your dmesg shows that the
drive is empty. Is it? My Seagate drive will have a
flashing yellow light if there is a hardware error
loading the tape, and will always return the above
message.

> probe(ahc0:0:0): Unexpected busfree in Message-out
> phase

What is this? I don't recognize this.

> st0 at scsibus0 target 0 lun 0: <Seagate, STT20000N,
> 7.27> SCSI2 1/sequential re
> movable
> st0: drive empty

As I was saying before, the drive thinks it's empty.
Your indicator lights on the drive may be of use if
the drive is not empty.

> nothing
> in /var/log/messages.
> 
> Any suggestions? Should termination problems give
> human readable 
> error messages? 

Nothing in var log messages means that you aren't
getting any errors from the scsi layer. Yes,
termination problems are usually related with human
readable messages. Well, usually is too strong.
Sometimes.

My best guess here is your firmware is tied in knots
and you need an upgrade, or you have a non recoverable
error in the drive logic or possibly the moving parts.
A shit deal all in all. My first plan of action would
be:

1. Attempt to clean the drive with a cleaning
cartridge. If it returns errors, then you probably
have a firmware or mechanical problem.

2. Look for new firmware or bug reports similar to
your own.

3. Check cabling. I'd think you'd get scsi errors if
it's wrong, but not always. This removes the
possibility of embarrasing yourself too...

4. Take the drive apart (don't void your warranty!)
and look for anything obviously wrong. There are many
things in a tape drive that can look obviously wrong
if you're not a tape expert though, so don't start
screwing with something if you don't know what you're
doing. What I mean by obviously wrong is grease on the
tape head or loose parts or something like that. These
things would probably cause strange messages to be
issued, but you never know.


In general, if you aren't getting any obvious error
messages, the problem is likely contained inside the
drive somewhere and not the device driver or the scsi
cabling. My feel is firmware.

I hope I wrote all this right...

Andy

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