Hi everybody.

There is a product for HA clustering, called Linux-HA (http://linux-ha.org).
The simplest requirement from the application is to keep all data files
on the same (shared) partition (say, /cluster); engine will start/stop/restart
applications as needed.

It it doable with Zimbra? Please, do NOT refer me back to Red Hat Cluster
Suite, I can read product specs :-)