There are two implementations available, one residing in kernel space and another one implemented purely in user space. If you wish to use the user space implementation of NFS, just enable nfs-server. To use the kernel implementation of NFS, activate nfs-utils for your target. Although kernel space is somewhat faster, this implementation has the drawback that only directory structures within a single mount point can be exported. So you have to supply at least a single entry for each mounted partition in /etc/exports. (Using the user space nfsd, you can also export the complete /mnt directory.
[label=sample /etc/exports] /mnt/disc0_1 *(ro,no_root_squash,insecure,no_subtree_check) /mnt/disc0_2 *(rw,root_squash,insecure,no_subtree_check)
Finally, start portmap and knfsd (nfsd when using the user space implementation):
[label=starting the daemons] # /etc/init.d/portmap start # /etc/init.d/knfsd start