/dev/rmt/0m:No such device or address

[Navin_3]

Hi

I am getting the following error when i work with backup & tape related commands.

"/dev/rmt/0m:No such device or address"

I tried with the following things but didn't work.

1, Changed the tape drive
2, Did insf -e
3, Changed the media

It was working till last week. Last week i did a reboot.From reboot it's not worknig. But when i do a ioscan, it's showing the device. Can anyone help me out.

Note : I am sure the drive doesn't have any problem. Bcoz when i use the same drive to someother machine it works.

Thanks in advance
Navin samuel

[Peter Godron]

Navin,
please check dmesg for error messages.
What exactly does ioscan report back?
Is the driver for the tape in the kernel (may have been lost in reboot)?
Regards

[Stephen Keane]

What does ioscan -Ctape -fn

give you ?

You aren't using ioscan with -k option? This will show what is in the kernel's cache, not do an actual device poll.

I sometimes get the same error, if the device is not ready (e.g. tape not loaded etc).

[harry d brown jr]

Try running "ioscan -f /dev/rmt/0m", like below:

[root@vpart1 /var/appl/perlscripts/LOGS]# ioscan -f /dev/rmt/0m
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
tape 0 0/0/1/0.3.0 stape CLAIMED DEVICE HP C1537A
[root@vpart1 /var/appl/perlscripts/LOGS]#

Does the "Driver" show up? and is the device "claimed" ?


live free or die
harry d brown jr

[Navin_3]

Hi all,

Thank you for your replies.

Dmesg is not showing any errors related to tape drive


Output of ioscan -f /dev/rmt/0m

root@holland>ioscan -f /dev/rmt/0m
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
tape 0 0/0/1/0.3.0 stape NO_HW DEVICE HP C1537A

You can note here the "driver s/w is showing as stape NO_HW instead of CLAIMED.

[Thierry Poels_1]

hi,

did you check the obvious:
- tape drive still has power?
- cables still connected firmly?

regards,
Thierry.

[harry d brown jr]

I know this reads like a stupid question, but is the tape drive turned ON ?

Also, but are the attributes of /dev/rmt/0m?

[root@vpart1 /var/appl/perlscripts/LOGS]# ls -l /dev/rmt/0m
crw-rw-rw- 2 bin bin 205 0x003000 May 28 2004 /dev/rmt/0m
[root@vpart1 /var/appl/perlscripts/LOGS]#

If you have another identical tape drive, swap them and see if the problem follows the tape drive.

You probably have a dead tape drive.

live free or die
harry d brown jr

[Navin_3]

I checked the cable & everything. It seems to be ok.

Pls find the ioscan -funC tape output

root@holland>ioscan -funC tape
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
tape 0 0/0/1/0.3.0 stape NO_HW DEVICE HP C1537A
/dev/rmt/0m /dev/rmt/c0t3d0BESTn
/dev/rmt/0mb /dev/rmt/c0t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c0t3d0DDS
/dev/rmt/0mnb /dev/rmt/c0t3d0DDSb
/dev/rmt/c0t3d0BEST /dev/rmt/c0t3d0DDSn
/dev/rmt/c0t3d0BESTb /dev/rmt/c0t3d0DDSnb
tape 1 0/0/1/0.4.0 stape CLAIMED DEVICE HP C1537A


It's showing two device, one with no_hw & one with claimed. I dont understand. If any problem in the scsi cable, will ioscan report claimed.

[John Payne_2]

Does your drive have a jumper or setting to change the SCSI id of the tape drive? IE your old one was set to SCSI is 3, and the new one is set to SCSI id 4?

That's what it kind of looks like.

John

[Peter Godron]

Navin,
looks like a problem with the SCSI ids.
Tape 0 is installed on ID 3.
Tape 1 is showing on ID 4.
Your device files are probably pointing to the wrong tape.
When you changed the tape drive did you check what scsi it had set. You may have signalled to the machine that a new drive is installed and then removed it again.
This tends to confuse the machine. May be easier to scrap and remake the device files after a clean reboot.
Regards

[harry d brown jr]

John is right, it appears the SCSI ID got changed and is NOW 4.

Turn the tape drive off, change the SCSI ID back to 3 - its the push button in the back of the drive. Turn it back on, and redo the IOSCAN.

live free or die
harry d brown jr