Tape drive scsi problems

[Fredrik.eriksson]

Well this seems like a dead thread at the moment... HP shunted us with some ridiculus notion that our Digital Alpha machines and Digital DLT7000 (aka 35/70-GB DLT Drive) tape drive isn't supported if we run OpenVMS :P

I'll get back to ya'll when we've solved that confusion :)

Best regards
Fredrik Eriksson

[David Lethe]

Sorry, I know you were trying to reach me to get details on that diagnostic software for tape drives that I copied the dump from. The software does NOT support VMS, but works with just about everything else including HP/UX on both IA64 & PA-RISC architectures.
The url for the manual is: http://www.santools.com/smart/unix/manual
and the software also has tapealert capability, along with ability to look at log pages, and even script something so you can watch for errors/warnings and set up some trigger during I/O.
You can get contact info from the website

[Hoff]

>Well this seems like a dead thread at the moment... HP shunted us with some ridiculus notion that our Digital Alpha machines and Digital DLT7000 (aka 35/70-GB DLT Drive) tape drive isn't supported if we run OpenVMS :P

You need be very careful with that word. Very careful. It's loaded.

In classic OpenVMS terminology, "supported" had very specific meaning. Likely still has it, too.

The word "supported" does not mean "it works". To the software folks, that word means "it works and we'll fix the code or replace the drive if it doesn't." It's that latter part of the definition that causes care around use of that word.

The DEC DLT series was typically not supported by OpenVMS. The DLT drives were platform-generic drives intended for OEMs. For details on what is supported, check the AlphaServer support matrix for your widget, and the device specs, and the OpenVMS SPD.

The TZ-series equivalent was supported. At various points in history, these TZ-series drives were based on the DLT series drive kernels.

HP is correct. The DLT7000 is not AFAIK supported.

The question is "will it work", and the answer to that is usually "yes", so long as you're patched to current and you're running V6.2 or later, and later is better.

If you're going to work with SCSI and particularly with SCSI device integration and testing (for drives that are not "supported"), you have to know how SCSI works. And how to troubleshoot the SCSI bus. This is at the core of why there's a specific interpretation of "supported"; the device firmware and host drivers can and do vary, and there can be oddities.

The same holds with ATA and ATAPI devices.

These devices are not as compatible as we might all want. (And "compatible" is industry code for "different". If the device was truly identical, it would be called "identical" and not "compatible". And the definition of "compatible" is nebulous at best.

Here, do some basic SCSI troubleshooting. Check the bus length and bus under- or over-termination, correct addresses, and start swapping parts, and do definitely double-check the termination. If you're doing SCSI device integration and testing work, you have to know how SCSI works. Or you'll learn how over time.

Or get some help in to have a look at this.

Here, I'd verify the bus configuration and integrity, and then swap the drive. I'd see if the problem moved with the drive, or stayed with the bus. (I have a DLT8000 around that I use for this sort of testing, as well as some supported TZ drives.)

Part of the reason why supported drives are more expensive is because specific configurations have been tested and are known to work; the drives are part of the host software and I/O controller compatibility test matrix. And because the vendor will swap bad drives or will fix bad software.

Stephen Hoffman
HoffmanLabs LLC

[Fredrik.eriksson]

Hi Hoff,

Well I do know the diffrence between "supported" and that it works.
But HP's response was all of a sudden that it wasn't _supported_ and the case is now closed. There was no problems right before christmas when they came the first time to replace the tape drives internal bits (because of a stuck tape).
I did describe it very shortly... the thing is (atleast as me and my boss read it) that they told us that our support deal is not a valid configuration (anymore?) if we run OpenVMS on the Alpha servers or if we run it with that tape drive.
But I don't know anything until thursday when I'm back at work and hopefully my boss has solved this mess :)

And my method is similiar to yours when it comes to testing which one is in error... I moved it to an identical Alpha server and it still does the same as earlier (I've written this abit up in the thread).

Anyway, I'll tell you all when this is solved... Either by HP or by us buying a shelfed one ourselfs.

Best regards
Fredrik Eriksson

[Fredrik.eriksson]

So, HP finally got here and changed my tape drive, and so far it's been working (since monday last week, knock on wood).

They didn't change the power supply thou, only the actual tapedrive since the new powersupply they brought didn't fit into the old powersupplybox.

Anyway, thanks again for your insight :)
Best regards
Fredrik Eriksson