HPE Nimble Storage Deployment Considerations for VMware vSphere 6Search

Base iSCSI Connectivity

For iSCSI connectivity between the vSphere environment and the HPE Nimble Storage arrays, the VMware ESXi host must have a minimum of two physical network interface cards (NICs). HPE recommends that you dedicate at least two physical NICs to iSCSI storage access. On the ESXi host, use the following NIC allocation model as a reference:
  • vmnic0 and vmnic1 (for management traffic, vMotion traffic, and VM traffic)
  • vmnic2 and vmnic3 (VMkernel ports for IP storage)

The VMware software iSCSI initiator is the preferred means for connecting to HPE Nimble Storage arrays by using the iSCSI protocol. You can use two connection methods to achieve HA and load distribution:

  • Method 1: One vmnic per vSwitch, and one VMkernel port per vSwitch
  • Method 2: Two or more vmnics per vSwitch, and one dedicated VMkernel port per vmnic

With both methods, the choice to bind VMkernel ports to the software iSCSI adapter depends on whether the ports are in the same broadcast domain and IP subnet:

  • When the VMkernel ports for software iSCSI multipathing are in the same broadcast domain and IP subnet, you must bind the VMkernel ports to the software iSCSI adapter. Array target iSCSI ports must also reside in this broadcast domain and IP subnet.
  • When the VMkernel ports for software iSCSI multipathing are in different broadcast domains and IP subnets, you must not bind the VMkernel ports to the software iSCSI adapter.

In addition, you must be sure to override the NIC teaming active-standby policy so that each VMkernel port is active on only a single vmnic. For detailed information about this configuration, see the HPE Nimble Storage VMware Integration Guide. For more information about whether to use iSCSI port binding, see VMware KB 2038869.

Although both connection methods allow ESXi iSCSI multipathing to provide high availability and load distribution for storage access, the second method has a slight advantage. It is easier to deploy and manage because only one vSwitch is required. If you use multiport NICs, ensure that iSCSI traffic spans different physical NICs instead of multiple ports on the same physical NIC. This approach prevents a single physical NIC failure from disrupting access to iSCSI storage. The following configuration illustrates this method.

Sample network configuration using two VMkernel ports and a single vSwitch

To prevent a single-switch failure that might cause a virtual infrastructure outage, HPE recommends that you use dual physical switches for the connection between the ESXi host and the HPE Nimble Storage array.