Openbsd_netboot_problems_ _unknown_error_code_72_

title: OpenBSD netboot problems - unknown error code 72 date: 2006-11-18 21:50:28

(Note: edited to actually be correct this time. :-)

While trying to get a Sparc machine to boot disklessly so I could install OpenBSD on it, I kept getting these errors:

Boot: bsd.rd
Automatic network cable selection succeeded : Using TP Ethernet Interface 
Using BOOTPARAMS protocol: ip address: 192.168.23.25, hostname: roark
root addr=192.168.23.10 path=/home/aardvark/openbsd-sparc64/chroot
open /sbus@1f,0/ledma@e,8400010/le@e,8c00000/bsd.rd: Unknown error: code 72

tcpdump showed that the machine was trying to contact the NFS server (192.168.23.10) by udp on port 0; the server kept responding with an ICMP port unreachable error. Googling turned up one other person back in '99 (!) who had the same problem, but no fix.

What was weird was that this had worked during an earlier install -- only the running of MAKEDEV hadn't completed (don't ask), so I didn't have /dev/console when I booted up, which meant no nothing once it tried to mount the root directory.

I started looking at the traffic in greater detail, and saw that the packet to port 0 was, according to Ethereal^WWireshark, a nicely formed NFS call trying to get the filehandle for the kernel (/bsd). Well, what would make it send it there? After all, mountd was listening on the same port it'd been contacted on a moment ago...

Looking at the call to portmap on port 111, I saw that the client was asking for the port for nfsd, but was being told that there was no such thing -- that the port number was zero. What the...I checked rpcinfo -p and saw that, yep, there was no nfsd...and then realized my mistake: mountd only deals with mount requests; it's nfsd that actually reads/writes files, gives information about their size and modification times, and so on. I'd been starting the NFS stuff by hand since this was a one-off, and had totally forgotten to start nfsd. I did so, and suddenly all went well. PEBCAK.