SUMMARY a device went offline...

From: Jacques Beigbeder (
Date: Mon Jan 11 1993 - 10:40:39 CST

The question was:

>> Due to an error, a tape device went offline.
>> Now the system says:
>> /dev/nrst1: no tape loaded or drive offline
>> Is there any way to have the device coming back online?
>> Of course, we can reboot but...

Three hints:
 1. first ensure the SCSI chain is in good conditions: length,
 termination, etc.
 2. try to turn the unit on/off.
 3. reboot.
But none of these tells how to have the device coming back on line!

Thanks to (Brent Chivers) (Mark S. Anderson)
        fourx.Aus.Sun.COM!ups!kevin (Kevin Sheehan {Consulting Poster Child}) (Todd L. Kindig @ Micom Comm. Corp.) (Peter Gross)
        Amir Ilbeig <>
        Chi-Yang Cheng /

After follows an answer specific to Exabyte:

Jacques Beigbeder | Internet:
Service de Prestations Informatiques | Bitnet : beig@frulm63
Ecole Normale Superieure |
45 rue d'Ulm | Tel : (33-1) 44-32-37-96
F75230 Paris Cedex 05 | Fax : (33-1) 44-32-20-80

The problem is that the 8mm tape drive gets in a state where it will not
accept a tape, any tape. Each time the tape is loaded into the drive, the
drive ejects it.


mt -f /dev/rst0 status

returns "no tape loaded or drive off line" message.


It seems that when Exabyte sells a drive to a vender, they do not know how
it is going to be used. So they put a generic set of PROMs in the device.
This set of PROMs just does not work well with SunOS, and UNIX in general.

The error that we are seeing is called a "servo system" error. The only way
to clear this is to reboot, or to power cycle the drive. The new level of
PROM will also allow a "soft servo" reset by pressing the eject button
while the tape door is open. Also, the new level of PROM will help prevent
this problem from occuring in the future.

The old PROM levels were:

         SVPROM B019
         MXPROM 425A

The NEW PROM levels are:

         SVPROM C034
         MXPROM 2618

Thank you,
Amir Ilbeig voice: 713-630-3820
Senior System Software Engineer pager: 713-736-9081
Cogniseis Development e-mail:
2401 Portsmouth _^_
Houston, Texas 77098 (o o)

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