Reading Mainframe Tapes
 

Hi,
We have recently installed a Linux based virtual tape system for our Unisys mainframe. The Linux server has a couple of SCSI tape drives attached to it that we use to import physical tapes to virtual tape. My question is - is there a standard Linux command that we could use to read the tape volume serial number from a tape loaded into one of the SCSI drives. The tapes are bog standard IBM mainframe tape format. Have read up about the 'mt' command, but think that I can only really use this to tell whether a tape is in the drive or not - it won't tell me what the tape serial number is.
Any suggestions?
Thanks,
John.

"IBM mainframe" has a fairly wide ambit - care to be more specific ???.

The tapes themselves are 3490E cartridges. I believe the tape format is known as "ANSI labelled". As they are mainframe tapes they will be written in EBCDIC and I'm pretty sure the tapes will have been written to using a fixed blocksize.

Each tape consists of a volume serial (volser) record that contains the tape serial number and the name of the tape as it is know by the mainframe. Then there are a couple of header records - not exactly sure what is held here. Then a "tape mark" after which the actual data begins on the tape. All I want to be able to do is read the volser record.

You might be able to dump the records via the dd command to a file and then analyze them for the desired information.

dd if=/dev/tape of=somefilename bs=xxx count=1

(change tape device name as desired)
Not sure what the block size should be.

Try this manual - chapter 3.

BTW "mainframe" != EBCDIC - not by a long shot these days.