One point, don't forget to backup the DB, which is stored in MySQL. It's great to have all the files back, but a missing DB will ruin your day... Frankly, I just include that in my tar statement
[~]# tar zxvf cpbackup.tar.gz /home/admispconfig/ /root/ispconfig/ /var/lib/mysql/db_ispconfig
Actually, I do my own script that also ftps it to another server and renames it with the date. But that is a little more involved.