Idea 1: Inside the VM sync to another VM
This sort of scenario might bode better as a master->slave configuration. You can configure the master with an LVM filesystem, take snapshots, and replicate them to the guest VM. The configuration would be entirely agnostic of the fact the systems were under Xen.
Rsync the Xen images from the dom0. See here for more details and directions.
backups are boring, but we all know
how important they are. backups can
also be quite powerful when working
with xen virtualization, since xen
allows for convenient back-up and
restore of entire systems.
i've recently been working on a
flexible, general-purpose script
enabling incremental backups of
complete xen guests, optimized for
secure, distributed environments;
xenBackup. if you're working with xen,
you might find it useful.
the xenBackup script leverages
open-source components like ssh,
rsync, and rdiff-backup to create a
simple, efficient and functional
all code and configurations have been
tested on debian etch but should be
useful for other *nix flavors with
subtle modifications. if you're
unfamiliar with xen, you might
consider starting with an earlier
how-to on setting up xen on your
debian etch box