Network and Storage Protocols

iscsi and nfs on the same vlan


I understand the best practice is to segregate the vlans when you want to put iscsi and nfs on the same node. Is there a good technical reason for segregating vlans for iscsi and nfs?



From TR3749

The use of multiple VMkernel ports is a defined standard method developed by NetApp and repeated by other storage vendors offering arrays with multiprotocol access. NetApp recommends defining a separate VMkernel for each storage protocol. This method makes the configuration of iSCSI with NFS very simple. Each of these VMkernel ports supports IP traffic on a different subnet. Using different subnet addressing schemes for iSCSI and NFS provides the benefit of being able to control which VMkernel ports are used for communication of each protocol. (An example is shown in Figure 31.) Because the two VMkernel ports are in the same vSwitch, they can share the vmnics in a vSwitch.

For NFS datastores, each VMkernel port is configured with a single active vmnic, with one or more standby vmnics defined. This allows the administrator to control which vmnic is used for traffic by each VMkernel port.