there is a backup script in /usr/share/astguiclient, start there (it includes ftp transfer to push to your spare)
you will also need any client recordings (of course, there's a function in crontab that can be activated to push those to an ftp server as well)
you'll want to set the system to auto-update the server ip (with the script in that same folder) at reboot, and another script to take all these files being sent and "apply them" after they all get sent every day. then if your primary system ever "dies" the spare will actually be a "hot" spare.
1) create all backups before midnight (so that if you "panic" and create a new backup because of a dying drive, you will NOT be overwriting THIS MORNING's backup, you'll be overwriting LAST WEEKs instead
)
2) copy all ftp recordings constantly and push to a non-related web server (archive), so they are independent of the vicidial system entirely (the ftp method will change the links in vicidial to point to them wherever you want them to be, as long as they are available on the web)
3) after the backups / files are moved, set the system to reboot and auto-update the ip address of the server ... BUT remember that any "Registrations" will interfere with the registrations of the REAL server, so you may need to disable the "carriers" until you actually go live (change the "Y" not "N" for active until you actually need it). Enterprise level carriers often have no registration, so also be sure that the IP address of the Hot Spare is AUTHORIZED at your carrier.