Getting Status of a DLT Drive

[Christian Valet_2]

I have a script that perform daily backup using fbackup. From time to time, I get an error message as follow:
fbackup(3041): output file /dev/rmt/1m is currently being used and not available

I suspect that the drive is doing some work on the tape when it is loaded. Is there a way I can query the drive controller for a status before I launch the fbackup program ?

Thanks,

Chris

[Rick Garland]

the mt -f /dev/dsk/cXt6XdX stat command

Or the mc command

Depends on version

[Christian Valet_2]

Rick,

I checked both commands mt and mc (I have both on my system). None of them really gives me the status i need. Although, mc -r provides what man call a status of a slot (FULL, EMPTY,NONE).

What i really need to query is if the drive is actually doing someting or if it is in ready mode.

My version is HP-UX 10.20

Thanks,

Chris

[John Palmer · Accepted solution]

What I do is to attempt to rewind the tape (mt rewind command) and check the response - 0=ok otherwise failed.

You can put this in a shell loop until success.

You are right about the DLT drive, it can spend quite a time after loading a tape (especially a new one).

[Rick Garland]

I show mt to be in /usr/bin.

If you were to do 'man mt' does anything come up?

The syntax would be something like 'mt -t /dsv/rmt/0m stat'
replace the 0m with whatever the the tape device would be.

[Christian Valet_2]

Rick,

It also shows in /usr/bin/mt,
yes, 'man mt' come up. But there are no stat command option in the documentation.
if i run 'mt -t /dev/rmt/1m stat' the message i get is the following:
mt: unknown command "stat"

Thanks for your help, I appreciate.

Chris

[Tom Danzig]

I don't think the "status" option for mt is available on HPUX 10.20 if that's what your running. The mt rew is probably you're best bet. If the drive is ready, it prints nothing and exits with status 0. If the drive is busy, it states so ("device busy") to standard output and returns non-zero (exit code 1 I believe).

[James R. Ferguson]

Hi:

I just checked this on a K570 running 10.20. First, the 'stat' option isn't documented.

On EITHER a DSS or DLT drive the messages returned from the operation: '/usr/bin/mt -t /dev/rmt/0m stat' are as follows (by case):


1. No tape -> /dev/rmt/0m: no such device or address

2. Tape in but not write-enabled -> /dev/rmt/0m: permission denied

3. Tape in and is write-enabled -> /Status 1 failed: invalid argument

In EVERY case the return code is one (1)

Clearly you can't rely on the exit code in 10.20. I suppost you could capture the error messages and act based on those, but this sure seems like a kludge. Regards!

...JRF...

[Carlos Fernandez Riera]

i was rewieving ...

1- mt stat is included in a patch available on ITRC

2- Use stm to get status of drive. also you can automatize this job. See : pam800200009131 Want to take a quick look at your Disk error Logs?

on HP Support Information Digests

[Christian Valet_2]

Hi Carlos,

I searched for pam800200009131, using the SEARCH in the ITRC. I might not looking at the right place (I'm a rookie in the marvelous world of HP!). Can you tell
me where to look ?

Basically what i want to do, is to make sure the tape drive is ready before i initiate the fbackup; otherwise i keep getting an error message telling me that the tape drive is
currently in use by another process, which is not true (i figured that the drive is still
winding the tape at that point of time).

Thanks everyone for your help!