Thanks to:
"Sean O'Connell" <sean_at_stat.Duke.EDU>
Anthony Talltree <aad_at_nwnet.net>
David Nicholson {DSLAK} <DavidN_at_datacom.co.nz>
Wesley Darlington <w.darlington_at_am.qub.ac.uk>
hl_at_tekla.fi
Eric Mermelstein <emermels_at_doas.state.ga.us>
alan_at_nabeth.cxo.dec.com
"Dr. Tom Blinn, 603-884-0646" <tpb_at_zk3.dec.com>
"John Richards" <john_at_zyqad.co.uk>
for the usual quick responses this group is famous for. My original
question, followed by some summaries and/or quotes from the responses
follows. The general concensus was that it would probably work, but
might take some fiddling to find the right switch settings,
parameters, etc.
Original question:
| I've been asked by someone else here at the university:
|
| Can a external HP 24 gigabyte DAT drive be connected to a Digital
| AlphaServer 2100 (4/275,Unix 4.0)?
|
| The story is, he bought the drive, figuring SCSI is SCSI and DAT is
| DAT, but DEC tells him that this drive can't be used with the
| 2100. His experience is also telling him that. But before punting, we
| want to be sure that there's not something that would make this work.
|
| (And if it won't work, what's the problem? Drivers?)
"Sean O'Connell" <sean_at_stat.Duke.EDU> says he has an HP SuperStore
DAT24 hooked up to an AlphaStation 500/266, and cautioned that there
is a Unix version and a non-Unix version. The Unix version should
work.
Anthony Talltree <aad_at_nwnet.net> thinks it's probably just a matter of
setting the right switch settings.
David Nicholson {DSLAK} <DavidN_at_datacom.co.nz> says he's used several
HP DAT drives with a few different systems.
Wesley Darlington <w.darlington_at_am.qub.ac.uk> wonders if gnu tar might
do a better job of talking to the drive. (I'm not familiar with what
has or hasn't been tried, or even if the device can be seen for gnu
tar to try.)
hl_at_tekla.fi says that he uses an HP1537A (24Gb DDS-3) in an
AlphaServer 2100 5/300 running 3.2c, and adds:
> Be aware that HP Drives has jumpers in the bottom, different settings
> for different vendors: DEC, HP, IBM, SUN.
> For DEC the switches should be:
> 1,2,4,5,7 on
> 3,6,8 off
Eric Mermelstein <emermels_at_doas.state.ga.us> writes:
> I'm not sure about your specific situation, but I had a similar experience with DEC tech support.
>
> I have an AS2100 that I wanted to connect a Sun DLT 4000 tape drive to. DEC said, sorry unsupported
> and it won't work. It took a couple of hours, but I did get it working and it has been running great
> since then (about 6 months now)! What you lose, is some of the functionality of the device.
> Especially if the drive is an autoloader or something similar. The reason is that non DEC devices,
> have different SCSI code pages and when the server queries the device as to what he is, he gets a
> response he can't interpret. That doesn't mean it won't work, it just means that the server/software
> you are using doesn't know (by default) about all of the tape devices features. (Have I confused you
> yet?) If you are using some backup software like NSR, pick the Digital device that is closest to your
> tape drive, manually define any additional capabilites and then it should work.
>
> There is one other alternative, which I haven't tried and I'm not sure how legal it is. You could try
> doing a firmware upgrade on the drive with a DEC firmware tape, which should rewrite the code page and
> make the tape drive think he was made by DEC. Most 4mm DAT drives are made by Archive, and ALL DLT
> drives are made by Quantum. The only difference is the label on the case and the code page/firmware.
>
> BTW, I have done the same thing with a Compaq 4mm Autoloader tape drive. It works too. I'm running
> DU 4.0b and NSR (Networker Save & Restore) for my backup software.
>
> Hope this helps. Please feel free to e-mail me back if you have any questions. And if you discover a
> better way to do this, please let me know!
alan_at_nabeth.cxo.dec.com writes:
> We do extensive qualification of the devices we sell to verify
> they work. When a device doesn't behave as expected (according
> to the SCSI-2 specification) we get the vendor to fix it. These
> are the devices listed as supported in the SPD and the Systems
> and Options Catalog.
>
> A random 3rd party SCSI device may or may not comply with the
> specification and even if it does, there is room for interpretation.
> I've heard it said that our engineering group believes our driver
> will work with any SCSI-2 compliant device. But, the customer
> believe the driver is at fault instead of the device, is responsible
> for proving that the driver is at fault. This nearly always
> requires a SCSI analyzer and knowledge to see what is really
> broken.
>
> Without more information I can't offer a suggestion of why
> it isn't working, but it should. There are always clear
> exceptions as well; CDROMs using a 2 KB sector size won't
> work until some future version, we expect 512 byte sectors.
> Some tape drives support internal block sizes that can be
> changed by software. Tapes written at one internal block
> size won't be readable on drives setup for the other. If
> one operating system sets one particular block size and we
> expected another, it won't work.
>
> SCSI is not necessarily SCSI and DAT is not necessarily DAT.
"Dr. Tom Blinn, 603-884-0646" <tpb_at_zk3.dec.com> writes:
> SCSI is SCSI, and DAT is DAT, but different vendors implement various tape
> drive features differently.
>
> I have no personal experience with HP DAT drives in general; we (Digital)
> have used them as a supplier in the past for some of the drives we've sold
> but we sell with a Digital label and often with Digital firmware so that the
> drive behaves in a way that's predictable to our software. In other words,
> when you buy our branded drive, we assure it will work.
>
> Being that as it may, you may be able to get the drive to work. However,
> you need to be running a reasonably current version of DIGITAL UNIX (V4.0
> is reasonably current, but there are fewer bugs in V4.0B or V4.0D), and you
> may need to add device specific entries to the ddr database for the drive to
> get it to work. Although it's possible that someone has done that already
> for the drive you have, you didn't state the EXACT model number, as seen by
> the system in response to SCSI commands, which is what would be used to look
> up the device specific characteristics in the database.
>
> There is a reference page for the ddr database, and some information about
> it in the database itself (in the text version).
>
> Hope this helps..
"John Richards" <john_at_zyqad.co.uk> writes:
> What does HP say? I've just added a HP DAT-DDS2 drive (not quite so meaty) with
> no problem. I've found that DEC say nothing will work with their kit unless
> it's DEC, and therefore expensive. I'd definately check with HP before
> quitting.
Geoff
--
Geoff Allen, geoff_at_wsu.edu, <http://www.wsu.edu/~geoff/>
Computers are useless. They can only give you answers. -- Pablo Picasso
Received on Tue Jan 13 1998 - 01:02:24 NZDT