VSM implementation
The VSM acts as a control plane for the N1KVsolution, that is, it is responsible for the vCenter communication, programming, and management of VEMs. Unlike the VEM, which is a code running in the hypervisor, it is actually a VM on an ESXi server. It can also be deployed on a dedicated hardware appliance, such as Nexus 1010. VSMs are typically deployed as High Availability (HA) pairs. Have a look at the following figure for more details:
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Please note that we can't have one VSM on Nexus 1010 and the other on the ESXi VSM.
Control plane controls multiple VEMS
Virtual machine running NX-OS