paul@prcrs.prc.com (Paul Hite) (05/15/91)
We have some gaps in our understanding of DAT drives on systems running HP-UX
7.0. We have a list of questions that we have prepared to give to our support
team. I thought that I'd post the list here in case anyone out there has the
answers. All of these questions have been posed to various support channels
in the past, but we either got no answer or many answers.
1) Model 1300H vs. unknown model used with 8x2 systems and hp-ux 7.0.
We have discovered that we have two different types of DAT
drives in McLean: the older 1300H used with CIO machines and
a newer (?) model used in NIO machines. We have some documentation
on the 1300H, but we have nothing on the newer model. What
documentation is available? We have experimentally determined some
of the differences, but is a complete list available?
2) How do we install hp-ux 7.0 on a 8x2 system with a DAT drive?
Our understanding is that DAT's are not supported as an installation
device with hp-ux 7.0. What is the supported way to recover from
the loss of the system disk with hp-ux 7.0 on an 8x2 system? Can
we obtain hp-ux 7.0 on DAT's?
3) The DAL 845's DAT will not work unless a cartridge is present at bootup.
While this system was in McLean, we could use the DAT drive without
having a cartridge present at bootup. Now that the system is in
Dallas, this is no longer true. The local HP CE told us that a DAT
drive will not work unless a cartridge is present at bootup. He has
proven this with repeated tests. The response center says that a
single error may be generated at bootup unless a cartridge is present,
but this should not affect later operation of the drive (A1760715).
The DAL 845 is in a state where the DAT drive is not usable unless
a cartridge is present. How did it get in that state? We are
prefectly willing to instruct all of our sites to have a cartridge
in the drive at bootup time if this is required. But we want all
(or most) HP personnel to come to an agreement on this issue.
4) What does patch p108 do?
We are aware that a patch to tape1 is available and indeed we have the
patch. The documentation that accompanies it is rather sparse. What
does this patch change? We have not installed this patch permanently
at any site. Should we?
5) Can we use /dev/rmt/0mn on a 1300H in emulation mode?
We have heard many answers to this question. The application note
(C1511-90906) says no in gray box inside front cover and again on
page 6. Then on page 9 it says that "mt" may be used to position
the tape. It has examples like "mt -t /dev/rmt/0m" which would
seem to be a no-op. The example "mt -t /dev/rmt/0m fsf 4" would
seem to be impossible unless the restrictions in that gray box
were lifted. All of the discussion of "mt" on page 9 is clearly
implying that multiple files on one tape are possible.
We have tried using the no-rewind bit and it seems to work. One HP
source told us that time-outs could result if we used the no rewind
bit. Another told us that it simply wasn't tested and might well
work.
As an aside, page 9 of the application note says that "mt" may be
used to eject the cartridge under software control. How is this
done?
Paul Hite PRC Realty Systems McLean,Va paul@prcrs.prc.com (703) 556-2243
You can't tell which way the train went by studying its tracks.