Check wether tape is writable?

[Danny Engelbarts]

Hi there,

Does anyone know if it is possible to check if a tape is writable without writing to it?

Greetz, Danny

[Rick Garland]

Check the 'write-protect' tabs.

[Tom Danzig]

If your're running 11.x, use mt status.

If the tape is writable, you'll get:

Drive: HP C1537A
Format: DDS-1 format
Status: [41111300] BOT online compression immediate-report-mode
File: 0
Block: 0

If it's write protected, you'll get:

Drive: HP C1537A
Format: DDS-1 format
Status: [45111300] BOT write-protected online compression immediate-report-mode
File: 0
Block: 0

Notice the words "write-protected" in the output.

[John Palmer]

Hi,

Not that I know of, 'mt status' doesn't seem to give any indication.

However if you position to end of tape (by mt fsf until it fails or mt eod for DDS drives) then you can reposition to the final tape mark (mt bsf 1) and then attempt to rewrite it (mt eof 1). The latter will fail if the tape is write proteced and if it works you've not changed any of the tape's contents.

The only problem with the above technique is the time that it can take to get to end of tape.

Regards,
John

[Patrick Wallek]

That status option on mt is supported in 11.0. I generally use the syntax of:

mt -f /dev/rmt/#mn status

I just used the command on my internal DDS drive and it works like a charm.