[comp.sys.apollo] 8mm tapes - oncec again

axtell@willow.cray.com (Maureen Axtell) (03/29/91)

I seem to have acquired an Exabyte 8mm tape drive and am having trouble
writing to it.  I'd like to use it with rbak/wbak.  The system is a
DN2500 running SR10.3 and the new tape library (/dev/rmts8, /dev/rmts12,etc)
are all in place.

Maybe I'm just being dense, but I don't understand how to use these
with "wbak -to"  and "rbak -from"  options mentioned in a previous note.

Any enlightenment would be greatly appreciated.

-maureen

thompson@PAN.SSEC.HONEYWELL.COM (John Thompson) (03/29/91)

> I seem to have acquired an Exabyte 8mm tape drive and am having trouble
> writing to it.  I'd like to use it with rbak/wbak.  The system is a
> DN2500 running SR10.3 and the new tape library (/dev/rmts8, /dev/rmts12,etc)
> are all in place.
> Maybe I'm just being dense, but I don't understand how to use these
> with "wbak -to"  and "rbak -from"  options mentioned in a previous note.

Contrary to what some people have said, I do not believe that it's possible to use
wbak/rbak and the 8mm tape drives -- if you use the standard Apollo utilities.  
This is assuming you do _NOT_ have Workstation Solutions (or equiv?) software.

I have tried several times since I read that you can use the 8mm drives and wbak, 
and I have nothing but failure to report.  I have tried using '-to' and '-stdout'.
I have redirected things until I was blue in the face.  I have tried using 
'-dev m0' as someone suggested.  Until/unless I hear differently from somebody
at HP/Apollo, giving O/S versions, wbak timestamps, and explicit instuctions,
I just plain won't believe it!

As for the use of '-to', '-from' etc, it's not too difficult.  When you use wbak,
you can specify ANY ONE OF
    -dev [c|m|f] -f <num>        
                  to put data out to (C)artridge, (M)agtape, or (F)loppy, 
                  and a tape-file-number.  Any tape-files _after_ the one 
                  written are lost, except to the truly dedicated adventurer.
    -to filename [-r] [-type uasc|unstruct|hdru]
                  to put data out to a filename.  Unless you use '-r', the
                  filename cannot exist yet.  If you use '-r', the filetype
                  is preserved from the current object.  (However, when I did
                  that to /dev/rmts8, I still got a large file that was of type
                  rmt_scsi, instead of having data go to tape.)  You can
                  specify a filetype (ascii, unstruct-ascii, or streams-header-
                  undefined) if it's necessary for some other application.
    -stdout
                  to put the data to stdout.  This lets you pipe things around.
                  It seems that most people claim to use this option when going
                  to an 8mm drive.
    -rem host:dev
                  to send data across a (tcp) network to a device on a remote 
                  host.  THe help file states that Domain/OS doesn't support
                  this (i.e. the remote host can't be an Apollo).  I don't know
                  about that, but /etc/rmt can't handle SCSI 8mm devices, at 
                  any rate.
When you're doing the rbak of the wbak'ed object, you simply use the inverse --
    -dev [c|m|f] -f <num>

    -from filename

    -stdin

    -rem host:dev


I have heard/read claims that 'wbak dirname -stdout > /dev/rmts8' works.  I have
also heard that 'wbak dirname -f 1 -dev m0' works.  As I said above, all I get
are error messages.  IBIWISI!  (I'llBelieveItWhenISeeIt)

-- jt --
John Thompson
Honeywell, SSEC
Plymouth, MN  55441
thompson@pan.ssec.honeywell.com

Me?  Represent Honeywell?  You've GOT to be kidding!!!

krowitz@RICHTER.MIT.EDU (David Krowitz) (03/29/91)

I've always found that "wbak -to" and "rbak -from" would not work with
device files such as /dev/rmts8 because "wbak" would check the file-type
and find that the device file was neither a UASC nor UNSTRUCT file. I always
used "wbak -stdout > /dev/rmts8". Or something like that. In practice, I
actually use the Workstation Solutions tape libraries so that I can put
multiple, labeled files onto a single tape set (ie. "wbak -f 2 //second_disk -dev m")


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter.mit.edu@eddie.mit.edu
krowitz%richter.mit.edu@mitvma.bitnet
(in order of decreasing preference)

goldfish@CONCOUR.CS.CONCORDIA.CA (04/02/91)

I don't have an Exabyte on my Apollo, however I do have one on my suns
and do my backups with something like:

	wbak -stdout -all //* | rsh mysun -l backup dd ibs=8k obs=80k of=/dev/exabyte

(where "backup" is the user on the target machine who trusts
Apollo-root and "/dev/exabyte" is the device for the exabyte)

On the Apollo, I would think that:

	wbak -stdout -all //* | dd ibs=8k obs=80k of=/dev/exabyte

would do the trick. (assuming that the SCSI device driver for  the
Exabyte can talk to the "dd" command

--	  Paul Goldsmith
<goldfish@concour.cs.concordia.ca>				 (514) 848-3031
	(Shirley Maclaine told me there would be LIFETIMES like this)