Backing up virtual machines in a VMware cluster should be done through the VMware vCenter Server. Normally, the VMware DRS (Distributed Resource Scheduler) cluster automation level is configured to be Fully automated for High Availability. This means the individual virtual machines that make up the cluster will be dynamically assigned to the best suited host at startup.

A virtual machine can be automatically moved to another host when the VMware cluster or virtual machine is restarted. If the virtual machine moves to another host, it will not be found by the DS-Client on backup and errors will occur. If the virtual machine is selected using the VMware vCenter Server IP address, the location of the virtual machine is always known, even if it moves to another host.

If you must back up a specific virtual machine in a VMware cluster with a dedicated backup using a specific host machine's IP address, you must configure the cluster to not move that virtual machine to different hosts: