I've recently started using a new NAS which runs CentOS 6.2. One of the purposes of the NAS would be to serve as a backup target. Whilst I have been using Apple's Time-Machine for a while and I am very satisfied with it, I'd like to continue using it.

Backing up directly to an address in my network is no hassle; all works fine.

For security reasons I'd like all my traffic to go through an ssh tunnel to the NAS. This way I can avoid needing to get a VPNserver (for personal reasons). As of NFSv4 the NFS deamon is bound to port 2049, which makes it easy for me to direct all traffic through a ssh tunnel.

Tunnel:

ssh -f admin@ms -L 2000:localhost:2049 -N

Mount:

mount -t nfs -o nfsvers=4,rw,proto=tcp,sync,intr,hard,timeo=600,retrans=10,wsize=32768,rsize=32768,port=2000 localhost:/mac_backup /Volumes/backup

This works fine for Finder/terminal and throughput is almost equal to direct traffic. (CPU of the NAS does ride high when I reach max bandwidth though)

Now the problem: With Time-Machine I can't use the NFS mount point mounted on localhost. TM seems to try to connect to it and then give me a "OSStatus error 65".

I also tried using NFSv3 (I correctly forwarded all ports) with no luck.

Can anyone shed a light on this and/or give a solution?