Since RedRocket wishes to use Rsync over SSH it would be best to use a Pro 2. Any method to use Rsync over SSH on an Ultra would not be supported by NetGear.
The Readynas Extra's SSH enabler add-on seems to work with Radiator 4.2.21 on Pro Pioneer, like Ultra with no Rsync SSH standard. We have 1 x Pro6, 1x Pro2 and an older Pro Pioneer and also online storage with rsync.
The only thing I did was change the ssh key for online backup as the hostname within the key didn't match coming up with nas-EA-57-F3
e.g. ssh-rsa AAAAxxxxxxxxxxxxxxxxxxxxxxxxxxBBBBCCCC== root@nas-EA-57-F3
I remember seeing that hostname in RAIDAR when setting the NAS up originally, I changed it to the current hostname, and added it to the /.ssh/authorized_keys file on the online storage server.
I discovered by accident keying in" .ssh/ " on filezilla the hidden folder would open with the key file which could be edited within filezilla instead of going through about with Putty.
If using a Readynas for online backup to hosted Rsync servers, it's necessary in my case to add " home/username/folder " in the Readynas Rsync path rather than just " username/folder" as in FTP/filezilla
