Stratus Technologies, famous for fault tolerant computers, the operating system VOS, and its newer ftServers line that can run Red Hat Enterprise Linux or Windows Server 2003 is giving away a book offer on Fault-Tolerance and/or Virtualization for dummies.  Get your copies here.

Stratus has two Virtualization options one for its hardware, another product is a software solution for commodity boxes.  1) VMWare, using the VMWare Infrastructure 3 on ESX,  2) Avance, which uses Citrix’s Xen and other HA components to build a pair of HA Virtual Servers.