I have a 4 bay running FreeNAS with a Raid 1 with two 6T drives. I would like to back it up to a 10 T drive on the same FreeNAS Hardware. Yes, I do have off site backup also. What is the best program to do this with? It would be nice if it was like the Synology backup software where a user can retrieve a file if needed.
you can do replication to from one pool to another.
I am looking for something like TAR or Hyper Backup on a Synology box.
Build another FreeNAS box and replicate to it or use syncthing.
Use ZFS replication feature, as Tom has suggested above.
ZFS replication will clone all the snapshots from the pool A (raid z1 in your case) over to the pool B (10 Tb hard drive), and will do so in an automated fashion, notifying you in case there is an issue of any sort (if you have email notifications enabled).