Phillip Pearson - web + electronics notes

tech notes and web hackery from a new zealander who was vaguely useful on the web back in 2002 (see: python community server, the blogging ecosystem, the new zealand coffee review, the internet topic exchange).

2007-5-28

Monster servers :)

Hah - our database server is currently handling 150+ queries per second, fairly happily on 1% CPU usage!

nfsmount (initrd) doesn't work with nfs-user-server, only nfs-kernel-server

I'm trying to do some hard disk maintenance on a machine on the other side of the world, and before I start doing things like reconfiguring its RAID arrays with things still mounted there, I'm giving NFS booting a go. The idea is to configure the system to boot using its usual GRUB boot partition, but then mount its root filesystem off an NFS server. This will let me unmount /boot and do all the hard disk maintenance, and if the worst comes to the worst, I can ask our man in the datacenter to bring the machine back to life with a Debian rescue disk.

I'd installed nfs-user-server on a Debian install on VMware, and configured a second Debian install to mount an NFS export from the server as its root partition. However, it would always fail during the boot with this error:

rpc failed: 2

At first I thought there was a module missing during boot or something, but I eventually figured out that the nfsmount tool used during boot was /usr/lib/klibc/nfsmount, and that it would give the same error if run after a normal boot:

/usr/lib/klibc/nfsmount 192.168.2.64:/nfsroot /mnt

The fix? Install nfs-kernel-server rather than nfs-user-server.

It now gets past that point OK. (It's still failing after 'Setting up networking....' -- I suspect that it's resetting eth0 and losing its IP address, or killing the NFS session.)