I've read the manuals and the options I've found are:
Use vSphere snapshots.
Use the backup/restore commands and export the backup to an external FTP server.
Using vSphere snapshots is not a viable option as we have restrictions on how long they can be kept. I'd prefer to use the backup command line tool on the virtual appliance but when I try I receive the following error:
Command not available in this configuration. Contact the product supplier for details.
Which worries me a little....
Can anyone clarify whether I can use the backup command on the virtual appliance please?