Subject: Dump device for diskless machine
To: None <tech-kern@netbsd.org>
From: Joe Landers <joe@hireindex.com>
List: tech-kern
Date: 06/02/2001 10:27:03
I'm trying to debug a kernel panic on MIPS-based diskless machine.
It would be great if I could get crash dump for later analysis with
kgdb, but I haven't been able to figure out how to configure a 
dump device for this configuration.

My fstab entries for the filesystem and swap are:

host:/usr/export/root  /     nfs   rw                 0 0
host:/usr/export/swap  none  swap  sw,nfsmntpt=/swap  0 0

which work fine. I can get the machine up into multiuser and
reliably panic the system. I've tried adding to fstab:

host:/usr/export/dump  none  swap  dp,nfsmntpt=/dump  0 0

but the mount fails. Since it's diskless, I don't have any block 
devices that I can configure manually with 'swapctl -D'.

Can I configure a diskless system to do a crash dump? How?

Joe Landers
joe@hireindex.com