I back up to my NAS via Ami-Back to a file. The only limitation is the 4 gig file size. With Ami-Back you can schedule the backup automatically. It is the most stable and capable Amiga backup program (
http://www.amibay.com/showthread.php?88189-Amiga-backup-software-comparison). You can patch it to version i from Aminet.
I also backup my NAS to an external HDD for additional protection and lock it in a safe.
I use SMBFS upon boot up so the NAS is part of the workbench right off.
To restore it couldn't be simpler...
1. I use the network boot disk (
http://jpv.wmhost.com/NetworkBootDisk/) and just boot right from floppy to my NAS.
2. Run HDTools if needed off the NAS.
3. Run Ami-Back off the NAS and restore. You could also just copy the files if you wanted at that point.