Floppy filesystem problems

[C.Eagle at massey.ac.nz]

We have recently installed a number  of diskless 3/80's  running off a
3/470 server (SunOS 4.0.3).

I am trying to  set up floppy diskettes   as small filesystems on  the
3/80's - I can mount and  use  the filesystem  on the diskette OK, but
umounting the filesytem causes the workstation to *crash*.

After the machine has crashed, reboots fail  with 'Parity error' until the
power is  cycled - even  a 'k2' boot  fails. Sometimes the machine must be
powered off for 3-4 minutes before it will reboot.

This does not happen if I umount straight after mounting (ie no access on
the filesystem),  but 'ls' on the  filesystem is normally enough to cause
the crash (sometimes it takes a bit more eg 'chmod -R').

I have  reproduced the problem  with 1.4MB  and  720kB  diskettes from
different manufacturers and on all our workstations.

I have spoken to the local Sun tech. person - they seem to think it is
something   to  do with our  running  the 3/80's diskless  that may be
causing the problem, and cannot offer any solutions.

Has anybody else seen this problem and/or know of a solution?

On a related matter, are there  any utilities for recovering data from
corrupt diskettes? 

Thanks for any advice,

			    Colin G. Eagle
		    Internet: C.Eagle at massey.ac.nz
	  Voice: +64 63 69099 x 7523	Fax: +64 63 505611
Dept. of Computer Science, Massey University, Palmerston North, New Zealand.