On Fri, May 07, 1999 at 04:48:58PM +0200, ks@ub.uni-mainz.de wrote:
> 
> hi,
> 
> I'm experimenting with a diskless setup and found that there's a
> really easy way to crash the client (amd486DX4/100, 3c509, Quantum
> TRB850A running netbsd-current)(*): just do a
>    dd if=/dev/rwd0d of=/dev/null bs=64k
> and the deed is done! :-/
> ok, that box's not completely diskless: I use the disk of this thing
> to get the netboot code from and for /var and swap. the kernel is
> loaded from an ss20 (running netbsd-current, of course), which holds
> the root and user filesystems for my client, too.
> 
> a backtrace on the client looks like this:
> _trap()
> --- trap (number 4) ---
> _wdc_ata_bio_intr()
> _wdcintr()
> _Xintr14()
> --- interrupt ---
> _idle()
> bpendtleep()
> _physio()
> _wdread()
> _spec_read()
> _nfsspec_read()
> _vn_read()
> _dofileread()
> _sys_read
> _syscall
> --- syscall (number 3) ---

Did it panic ? If so, what's the panic message ?

> 
> on the server I see the following line in /var/log/messages:
> 
> May  7 15:27:49 dino /netbsd: nfsd send error 64

This is "EHOSTDOWN", which means that your client didn't anserw ARP requests.
Quite possible if is was crashed :)

--
Manuel Bouyer <bouyer@antioche.eu.org>
--