Actually, I've been reading about the corosync, iSCSI, drbd, libvirt
approach. The only thing I don't like about this approach is that you
actually need to access the Guest/Domain in order to provide the HA
service.
My optimal solution would be one that doesn't need you to touch the
Guests/Domains in any way and, at the same time, provides HA for
storage and computing resources.
While I write this, I can't imagine a good way of sharing the Guest's
RAM so it is replicated on other hosts. This seems like cluster-like
functionality.
Is it feasible to setup a cluster or grid which share RAM so a single
kernel manages all hosts or something?