"You may need to have information replicated between
two computers that actually are part of a cluster, in addition
to"software" replica mechanisms such as Rsync you can use a product
that is stable and included in the standard kernel: DRBD.
"DRBD (Distributed Replicated Block Device) is a distributed
storage system for the GNU/Linux platform. It consists of a kernel
module, several userspace management applications and some shell
scripts and is normally used on high availability (HA) clusters.
DRBD bears similarities to RAID 1, except that it runs over a