I am trying to boot a server using a root partition on NFS. There are many web hits on this topic, but none seem very recent, and none that I found addressing this particular issue. The problem is that the last thing that comes out on the console is

nfsmount: error mounting /dev/nfs on /sysroot as nfs: No such file or directory

But a few more details on just what it can not find (host, file, ..) woluld be helpful. I could not find a kernel param that offered more logging (debug does not help here).

What I did was
1) add nfs support to the kernel ( CONFIG_NFS_FS=y ... ) and put it in /boot
2) make the root an nfs mount in /etc/fstab (on the nfs root)
3) mkinitrd --fstab=<the above file> for a new initrd... in /boot, and this seems to have done the right stuff (i.e. looking into the init script).
4) put an entry into /boot/grub/menu.lst that says
kernel /vmlinuz-2.6.27.20_nfs.x86_64 ro root=/dev/nfs nfsroot=10.3.1.222:/perf_linux_share/diskless_roots/poc06 rhgb quiet

The share 10.3.1.222:/perf_linux_share/diskless_roots/poc06 does in fact exist, thout /perf_inux_share is what is exported not the sub-directory, is that ok? (I am not restricting sub-dir mounts). If I just cut and past the nfsroot=<arg> into a mount -t nfs <nfsroot arg> /mnt it works fine.

I tired adding all the ip= (aka nfsaddr=) stuff but that did not help. I get the same error even if the target root on nfs is in fact missing (i.e. renamed) so I'm guessing it can not find it, but I don't see why.

Anyone know how to get more info on what is going wrong?
-jrg