I am using Slackintosh 12.1 as my host machine and connecting a 1TB external ext2 fs HDD as my shared nfs drive.
This one took hours and hours and lots of time on ##slackware channel with a lot of friendly people to help me out. I will not post their names because I did not ask for permission.
login as root:
On Slackintosh (host) chmod +x /etc/rc.d/rc.nfsd
/shared/folder client.ip.address(rw,no_root_squash) other.client.ip.address(rw,no_root_squash)
portmap: client.ip.address , other.client.ip.address
lockd: client.ip.address , other.client.ip.address
rquotad: client.ip.address , other.client.ip.address
mountd: client.ip.address , other.client.ip.address
statd: client.ip.address , other.client.ip.address
/dev/??? /mnt/point fstype user,rw,auto 0 1 (Since mine is an external i have this entered. yours may not be an external, if it is already being mounted in fstab, skip this portion).
ON CLIENT MACHINES
login as root
chmod +x /etc/rc.d/rc.rpc
ip.to.host:/shared/folder /mnt/point nfs rw,nfsvers=3 0 0
It should now be mounted and you should have rw access to that drive as user.
The chmodding we did earlier will ensure that nfs services for the host and client machines will be turned on at bootup. And the line in your client fstab ensures that nfs system will auto mount at bootup.