On each vSphere host, a VMkernel port for vSAN communication must be created and used for synchronization and replication activities. The VMkernel virtual adapter type has been added to vSphere for vSAN. This VMkernel port is labeled vSAN traffic. This port group is typically dedicated and isolated to vSAN communication. However, if a 10-GbE network interface is being employed, it can be shared.

For 1-GbE networks, VMware recommends using a dedicated port group, dedicated network card, and an isolated network for vSAN traffic. This also increases security and prevents other traffic from impacting the performance of vSAN.

As highlighted previously, the VMkernel interface is used for host intra-cluster communications as well as for read and write operations whenever a vSphere host in the cluster is the owner of a particular virtual machine, but the actual data blocks making up that virtual machine’s objects are located on a remote host in the cluster. In this case, I/O must traverse the network configured between the hosts in the cluster. If this interface is created on a VDS, the Network I/O Control feature can be used to set shares or reservations for the vSAN traffic.