VMCL is the first free high availability software for VMware
environment, It's based on famous
Linux-HA cluster software.
It manages virtual machines failover when a physical host crashes
VMCL has a feature actually not available in any other commercial
product: it decides which available physical host has to start faulty
virtual machines depending on specific parameters (free memory, CPU
usage) to be respected and considering a defined priority.
The whole thing is based on a quorum disk (a VMDK formatted ext3)
created for every physical host, where every virtual machine
configuration file (.vmx) is copied and synchronized.
When a physical host is faulty VMCL will decide which remained
physical host has to mount faulted host quorum and to start which
For heartbeat documentation refer to web site