mtx with 1/8 SDLT 320 Autoloader

[Nathan Price]

I have my HP SDLT autoloader connected to a server running Redhat ES3.
I'm using the UNIX program mtx to control my HP autoloader. Mtx and the changer work well together for most things - I can get carousel status, load/unload tapes from the drive and generally control the carousel. But I can't figure out how to get mtx to perform the import/export functions available from the front panel: ie. actually get tapes in/out of the changer under program control. Does anyone on this forum have any experience with this?

[CA713937]

I will take a guess that the 1/8 autoloader does not actually support a move media command to move a tape to the import/export slot, and the only way you can do that is via the front panel. Since someone needs to be in front of the autoloader to actually take the tape out (which is blocking the robotics from moving), there's little advantage if initiating this remotely (other then saving a few button presses).

[Nathan Price]

David -
You may well be right. Being able to export/import programmatically isn't that much of a help since someone still needs to physically move tapes in and out of the I/E slot. My question was motivated partially by curiosity and partially to remove opportunities for human error in pushing front panel buttons.

[CA713937 · Accepted solution]

> Being able to export/import programmatically isn't that much of a help since someone still needs to physically move tapes in and out of the I/E slot.

And as I said, the robotic is blocked from any other operation until you do. For a normal I/E slot (or mail slot or load port) in a tape library, you can move a cartidge to the I/E slot, and the robotics can continue to operate.

> My question was motivated partially by curiosity and partially to remove opportunities for human error in pushing front panel buttons.

Yes, I can see that would be useful.

The 1x8 autoloader is somewhere between a pure autoloader-only device (which can only load tapes sequenally) and a tape library (which can load tapes in random order).

Just for a bit of background, from SCSI, libraries (actually called medium changers) have 4 possible elements it can manage - drives, storage slots, transport elements, and import/export slots. The 1/8 autoloader only supports type types of elements - slots and drives (actually just one drive), and you are limited to moving a tape currently in the drive back to the slot it came from.

The mt (or mtx) commands in unix use the read element status command results from the library/autoloader to determine what elements are present, and what moves are possible. The 1/8 will only report that it has slots and a drive.

Although the 1/8 autoloader uses the terms import/export for loading tapes via the front panel, it is not actually an import/export slot from a SCSI perspective.

Hopefully that explains why you can't do what you think you should be able to do.

[CA713937]

FYI, I stumbled on a document that explains why the import/export slot is not a software import/export slot:

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000079745364

[Nathan Price]

Yup, that document explains exactly what's going on with the lack of software support for import/export. And it's really not much of a limitation since a human being has to be standing at the rack anyway to move tapes into or out of the unit.

Thanks again.