I'm running unRAID v6.2.4 and trying to mount a share via NFSv4 from a linux client but it doesn't seem to be enabled/supported.
# mount -t nfs4 nas:/mnt/disk1 /mnt/disk1
mount.nfs4: Protocol not supported
# rpcinfo -s nas
program version(s) netid(s) service owner
100000 2,3,4 local,udp,tcp portmapper superuser
100024 1 tcp,udp status 32
100003 3 udp,tcp nfs superuser
100021 4,3,1 tcp,udp nlockmgr superuser
100005 3,2,1 tcp,udp mountd superuser
EDIT: So it looks like NFSv4 requires a bit of work to be functional on Slackware.
http://www.linuxquestions.org/questions/slackware-14/does-slackware-14-1-or-current-have-nfsv4-support-4175550162/
Assuming that's correct, can a mod/dev look into this? Or correct me in the event I'm wrong.