Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!ncar!asuvax!mcdphx!mcdchg!att!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Backing up PC's over a network?
Message-ID: <9818@chinet.chi.il.us>
Date: 19 Oct 89 14:41:48 GMT
References: <3029@tahoe.unr.edu> <9792@chinet.chi.il.us> <6183@tekgvs.LABS.TEK.COM>
Reply-To: les@chinet.chi.il.us (Leslie Mikesell)
Organization: Chinet - Chicago Public Access UNIX
Lines: 27

In article <6183@tekgvs.LABS.TEK.COM> keithe@tekgvs.LABS.TEK.COM (Keith Ericson) writes:

>OK, got that done, and install the Wollong TCP/IP and NFS packages.  Make
>the link from /usr/me/tape to /dev/rmt/c0s0 (and tapen --> c0s0n).  Turn
>back to the DOS/PC-NFS machine to see what I can do.  Not much...  The files
>"tape" and "tapen" simply don't exist, EXCEPT that I can't create a file named
>tape or tapen in the /usr/me directory, so it kinda' knows it's there.  Dir,
>ls, and PC-NFS's "ls" command all fail to report the presence of the "tape"
>file.

How about FIFO's?  Can you:
/etc/mknod fifo p
and see the resulting fifo from the DOS machine?  If so, you might be
able to execute:
dd <fifo >/dev/rmt/c0s0   from unix
and write into the fifo from dos  (reverse to read).
This was the approach that I tried first, but the Starlan Dos server
apparently sets the O_NDELAY mode which makes a write() return with
an error if the pipe fills instead of waiting for the process on the
other end to catch up (pretty useless IMHO).  I would prefer to
use something like that because it would allow talking to an arbitrary
unix program from any dos program that reads/writes files sequentially,
and in the case of the tape drive it would allow reasonable block sizes
to be used to keep the tape streaming longer.

Les Mikesell
  les@chinet.chi.il.us