Runaway mt erase

[Bill Voight]

Sports fans,

I was having some trouble with an 8mm tape in one of our Sun 2000E's, so
I ran mt erase in the hope of solving my problem. As is so often the
case, I've created another.

The thing appears to have run away. The tape appears to be doing
something, but kill -9'ing the process doesn't work even though it shows
an exit code of 0. I tried killing the parent (terminal) process, that
also did nothing. I tried ejecting the tape, that did nothing.

This box also has a DLT4700 mounted as /dev/rmt/1. I noted that
although the tape server for ARCserve appears to be running, ARCserve's
device management doesn't want to run. Related? Who knows?

Of course, I can bounce the server (it's development), but I'm
interested in what went wrong. Any ideas?

Thanks,

BV

[Brent Burkholder]

Bill Voight wrote:
>
> Sports fans,
>
> I was having some trouble with an 8mm tape in one of our Sun 2000E's, so
> I ran mt erase in the hope of solving my problem. As is so often the
> case, I've created another.
>

I don't know how 'mt erase' is implimented, but it's entirely possible
that it issues a single scsi format command to the tape drive. Once
this command hits the tape there's nothing you can do to stop it
short of powering it down.

> The thing appears to have run away. The tape appears to be doing
> something, but kill -9'ing the process doesn't work even though it shows
> an exit code of 0. I tried killing the parent (terminal) process, that
> also did nothing. I tried ejecting the tape, that did nothing.
>

You killed a process that was simply waiting for the scsi command to
finish up before it returned. No effect...

Brent

[Galen Arnold]

Brent Burkholder (bb...@bicnet.net) wrote:

: Bill Voight wrote:
: >
: > Sports fans,
: >
: > I was having some trouble with an 8mm tape in one of our Sun 2000E's, so
: > I ran mt erase in the hope of solving my problem. As is so often the
: > case, I've created another.
: >
:
: I don't know how 'mt erase' is implimented, but it's entirely possible
: that it issues a single scsi format command to the tape drive. Once
: this command hits the tape there's nothing you can do to stop it
: short of powering it down.

This is the case with most scsi tape drives. An "mt erase" get's handed off
to the drive for completion and cannot be interrupted once issued.
--
____________________________________________________________________________
Galen W. Arnold, systems programmer/analyst arn...@cheyenne.isgs.uiuc.edu
Illinois State Geological Survey, Champaign, IL 61820 (217) 244-2514
____________________________________________________________________________

[Casper H.S. Dik - Network Security Engineer]

[[ PLEASE DON'T SEND ME EMAIL COPIES OF POSTINGS ]]

arn...@geoserv.isgs.uiuc.edu (Galen Arnold) writes:

>Brent Burkholder (bb...@bicnet.net) wrote:
>: Bill Voight wrote:
>: >
>: > Sports fans,
>: >
>: > I was having some trouble with an 8mm tape in one of our Sun 2000E's, so
>: > I ran mt erase in the hope of solving my problem. As is so often the
>: > case, I've created another.
>: >
>:
>: I don't know how 'mt erase' is implimented, but it's entirely possible
>: that it issues a single scsi format command to the tape drive. Once
>: this command hits the tape there's nothing you can do to stop it
>: short of powering it down.

>This is the case with most scsi tape drives. An "mt erase" get's handed off
>to the drive for completion and cannot be interrupted once issued.

mt erase will take several hours to complete.

Casper
--
Expressed in this posting are my opinions. They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.