How to make the transition as seamless as possible? I found out the hard way, it’s not as easy as remounting with -t nfs4!

server is already exporting /home through /etc/exports

/home 10.4.91.0/24(rw,no_root_squash,async)

Create the NFS4 pseudofilesystem:

mkdir /NFS4
chmod 777 /NFS4

Create a place for /home to go

mkdir /NFS4/home
mount –bind /home /NFS4/home

make it permanent in /etc/fstab

/home /NFS4/home none defaults,bind 0 0

export /NFS4 and /NFS4/home. /NFS4 must have fsid=0 to indicate it’s the root of the pseudofilesystem

/home 10.4.91.0/24(rw,no_root_squash,async)
/NFS4 192.168.1.0/24(rw,fsid=0,no_subtree_check,sync,no_root_squash)
/NFS4/home 192.168.1.0/24(rw,no_subtree_check,sync,no_root_squash)

because of this NFS4 pseudofilesystem stuff, clients don’t mount /NFS4/home, they mount /home! If you have -t nfs4 then it’s actually mounting /NFS4/home, otherwise it mounts /home through NFS3.

Going to test this a couple of times to make sure it’s correct, cranking out another xen instance (yay for kickstart!) to make the tests more accurate.