Typically most DR sites are single direction failover – Prod storage replicating over to a DR Site (active/passive). SRM requires a licensed VMware VirtualCenter at both protected and recovery sites because both VMware VirtualCenter instances are active instances. SRM also requires enough VMware Infrastructure licenses at the recovery site to meet the minimum resource requirements of the virtual machines that are configured to fail over to the recovery site at all times. The VMware Infrastructure licenses at the recovery site can be used to run other virtual machines, such as your Dev environment, even while being part of a VMware Site Recovery Manager configuration. At the time of a disaster you can run a job to shut down all or some VM’s at the DR site. Refer to diagrams below for configuration examples.
Single-direction failover. Requires licenses for 2 VirtualCenter Management Servers, 10-CPU VMware Infrastructure, and 6-CPU Site Recovery Manager.
Bi-directional failover. Requires licenses for 2 VirtualCenter Management Servers, 10-CPU VMware Infrastructure, and 10-CPU Site Recovery Manager.
So in conclusion you actually only need to licence all CPU’s holding VMs you are protecting, and you can run less servers in your DR but planning needs to be done to make sure you have enough resources to sustain the load for your Servers when they fail over.
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