NFSv4?

I'm trying to get an nfsv4 server running with Kerberos auth. The usermode server package is inappropriate because it doesn't support locking. So.

Stock xen kernel, 2.6.18.8-domU-linode7 doesn't contain nfsv4 support or rpcsecgsskrb5. These are obviously both required.

However, nfs support is included in the default server.. sans nfsv4. Since nfs is compiled in, and all of nfs is a single module, I can't simply add nfsv4 support to the kernel as a module. When I try to do turn nfsd into a module and compile that, I get:

cdodt 1 ~% sudo modprobe –force nfsd

WARNING: Error inserting exportfs (/lib/modules/2.6.18.8-domU-linode7/kernel/fs/exportfs/exportfs.ko): Invalid module format

FATAL: Error inserting nfsd (/lib/modules/2.6.18.8-domU-linode7/kernel/fs/nfsd/nfsd.ko): Device or resource busy

This is because they contain overlapping symbols with stuff compiled into the kernel statically.

Anyone have any suggestions for getting working nfsv4 with Kerberos?

[Edited error messages above.]