SUMMARY: Problems with bar

From: Monty Peffley (
Date: Wed Nov 18 1992 - 19:49:42 CST


> We are using SunOS 4.1.2 and 4.1.3. When trying to read a floppy
>diskette which has a second volume, I cannot seem to get "bar"
>to work. I am using a remote shell on an SS2 and an IPC. It should
>work just like "tar" but does not. The form I have tried is:
> rsh -n remotesystem dd if=/dev/rfd0 | bar xvf -
>I have also tried using a blocking factor of 20 as shown in the
>man pages. I get part of the file, then get a read error: Error 0
>message. It clearly objects to the multiple volume. Any suggestions?


  On the suggestion of several responders, I got it to work by extracting
the file locally. How simple! On one of our systems with a local diskette
drive, I used:

   bar xvf /dev/rfd0

then ftp'ed the files to where I wanted them. Thanks to all those who
                  Cecile Ingram (
                  Monty Peffley (


1. wrote:
On the off-chance that no bar experts give you a solution, have you tried to
just copy the 2 volumes to disk and then send them to bar across the net? ie,
on the system with the drive:

dd if=/dev/rfd0 > part1
<change disks>
dd if=/dev/rfd0 > part2

now on the target system:

rsh -n remotesystem cat part1 part2 | bar xvf -

2. wrote:
Do you realise that with the above command, you are reading the diskette
on the remote system, but running bar on the local system. You could try:

rsh -n remotesystem "dd if=/dev/rfd0 | bar xvf -"

but I suspect you may still have trouble when bar comes to tell you to
change the diskette. How are you going to do that on a remote system anyway?

3. wrote:
My guess would be that bar looks at the device it's reading from to
determine if it is a "multiple-volume" device. Since you have it
reading from stdin, it doesn't think there can be multiple volumes.
Have you tried extracting it file locally?

4. wrote:
bar won't handle multiple volumes when stdin is used. Can you run
bar on the remote system instead?

5. wrote:
Bar knows how to span volumes and eject and request for a new floppy, but dd
does not. Because of this, bar will almost surely not work across multiple
volumes except on a local machine. There is also a sentence at the end of the
bar manpage..

     If you specify `-' as the target file and the archive spans
     volumes, the request for a new volume may get lost.

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:53 CDT