Non Availability of the Tape device

[Milan Muralidharan]

When i tried to use the DDS tape device for archiving some files i get the error message
"tar: cannot open /dev/rmt/0m ".
I was using the same device for archival tow days back and it was working.
Please inform what could be the cause of it?
If the Tape device is full :
1. Then how could i extract the previously archived files?
2. How could i clean the filled tapes?

Appreciate your details.

[Paul Hite]

Probably, some other process has it open. Try "fuser /dev/rmt/0m".

[Eddie Warren]

Milan,
If tar cannot open the device. The system might be having a problem communicating with the device. Try "ioscan -fnC tape" and see it /dev/rmt/0m is available. It it is available, use a new tape and try the "mt" command. for exampe: mt -t /dev/rmt/0m rew
There are quite a few symptoms to cause this,
as mentioned previously, another process might have it open.

[Milan Muralidharan]

'fuser /dev/rmt/0m' is not showing up any details or errors.

ioscan shows the status as 'CLAIMED' for
all the three devices(1m,2m & 0m).
I could able to use /dev/rmt/2m now for archival processes but not 0m & 1m .
Why is this?

[John Palmer]

Milan,
Are you trying to read from or write to the tape?
If writing, could it be that the tape is write protected? Check the small tab on the tape itself.
As was stated earlier, use
mt -t /dev/rmt/0m rew
to check that a tape is correctly loaded.
In order to clean the drive, you need a special cleaning cartridge. Just load it in the drive and it will cycle and unload automatically.
Be aware though that DDS drives do tend to wear out after a lot of use. Unlike DLT drives, the tape does contact the heads and causes wear.
Regards,
John

[Ray Evans]

If you are unable to use only the /dev/dsk/0m file, it may be corrupt. Try recreating the device file using insf and necessary switches.

[Carlos Fernandez Riera]

See device leds an compare whit documentation.

1- use a cleanning tape

2- use a new tape acording to drive specs. ( driver DDS2 tape 120m, drive DDS3 tape 125m ....

3- Ensure tape is not write protected.

4- use command mt -t /dev/rmt/0m status. There is an individual patch that implemtents this function. Search on Pacthes.

5- See /var/adm/syslog/syslog.log for alters or errors in this device.

[CHRIS ANORUO]

Milan,

Do a cd /dev and run insf -d (driver) or -D (directory).
This will recreate the drivers and directory for the tape.

[Milan Muralidharan]

Thanks for the details. I still want to know how to clean a filled in tape or to recycle a tape.

[Patrick Wallek]

To use a tape that has been previously written on, just write data to the tape again.

Make sure the tape is rewound (mt -t /dev/rmt/0mn rew) and then do your tar or whatever you want to do on that tape. Tar will write over whatever is on the tape, it doesn't care if there is already existing data on the tape. As long as the tape is NOT write protected, you can write over whatever is there.