The tape drive is power off

[eric_204]

I am testing the new backup software , but now when I use the tar command to backup file to the tape , it pop the below message , could suggest what can I do ? I use DDS4 and RH7.2 system . Thx in advance.

/dev/tape: No medium found
mt: The device is offline (not powered on, no tape ?).

[eric_204]

I also found the below error in /var/log/messages , could suggest what can I do except reboot the system ? thx.


kernel: st0: Write not multiple of tape block size.

[Alexander Chuzhoy]

Try to create a symlink like this:
ln -s /dev/st0 /dev/tape
or
ln -s /dev/nst0 /dev/tape (no rewind)
Best regards...

[eric_204]

thx Alex , the path has been connected , what else i can do ? thx.

[Stuart Browne]

Make sure that the tape is being recognised by the OS. Use the 'dmesg' command (or the log file /var/log/dmesg), looking for references to 'st0'.

Whether you can see it there or not depends on two thigns. One is that the device is seen at all (look in /proc/scsi/scsi), and the second is whether the 'st' module is installed (or compiled in).

Use 'lsmod' to see if the 'st' module is installed. If not, 'modprobe st' to install it.

If you've done both of these, and you have a device called '/dev/st0', then use 'mt -f /dev/st0 status' to see if you get a response from the tape.

You've not said if the tape is internal or external by the way. In any case, it might just be a loose cable.

[Steven E. Protter]

Look at tape drive.

Run the tar command.

see if any lights light up.

If not, check the power connection, most of them will blink when there is a write attempt.

This could be as simple as the write protect tab on the tape.

SEP

[Runar Jørgensen]

Greetings

I've been down this road before (ref.:http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=198605) with no luck. Not to
reduce your hopes though.

*) what's in your proc-directory
(cat /proc/scsi/scsi) You should see if the kernel has recognised the device there.

*) You might also want to check that there has'nt been a change in your /etc/modules.conf.

*) Did the new backup software change something with the dev-files? It should look like something soimilar to this.

$ ls -la /dev/st0*
crw-rw-rw- 1 root disk 9, 0 Mar 17 2003 /dev/st0

*) I guess you've tried the dd-command? No? what about
dd if=/dev/st0 bs=256k count=1 of=/tmp/test

That's basically what I can think of at the moment. Alas I didn't get my HP1529 to work. Hope you're more successful.

Regards,
Runar Jørgens

[Bill Thorsteinson]

There are a couple of tools that may help.

The scsitools collection contains a tool to list the attached devices. It should list your tape drive.

There is also a scsiadd tool which will do the necessary magic to add a device that was powered off at that last boot.

[Ram Prasad_1]

*****************************************************
I also found the below error in /var/log/messages , could suggest what can I do except reboot the system ? thx.


kernel: st0: Write not multiple of tape block size.
*****************************************************

Solution:
run: mt -f /dev/st0 setblk 0

The you will be able to use the tape and not get the above error message