Quoting from the Double-Take official announcement:
Further broadening its offerings for VMware environments, Double-Take® Software today announced Double-Take for VMware Infrastructure, a solution that protects entire VMware virtual machines.
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Double-Take for VMware Infrastructure runs on a single Windows® server in a virtualized environment, and allows administrators to centrally manage and monitor multiple virtual machine protection jobs from any Windows desktop using the client management console. Double-Take for VMware Infrastructure captures changes regularly, keeping the target virtual disks up to date and ready for failover, recovery and backup at any time. During an outage, the replicated virtual machine can be started on the target server with the latest replicated data available.
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Double-Take for VMware Infrastructure is compatible with VMware ESX Server versions 3 and later, and VirtualCenter version 2 or later.