I have Proxmox also running in a hosted environment where i only geht ftp backup space.
So i added a curlftpfs mount on the local filesystem. There i can't backup a large VM because it eats up all my RAM. It would be nice to have an option, that does not tar the Archive, but simply rsync the incremental data.

I found some code in the openvz forums:


Did you guys review this?