Specifications

Figure 3 SRM Environment Layout

4.2 IP ADDRESS CHANGES

Some environments may be able to use the same network IP addresses at both the primary site and the DR

site. This is referred to as a stretched VLAN or stretched network setup. Other environments may have a

requirement to use different network IP addresses (in different VLANs) at the primary site than what is

configured at the DR site. SRM supports both of these scenarios.

VMware provides a tool called the dr-ip-customizer to assist with configuring SRM to automatically update

VM IP address and network information (such as primary and secondary DNS server settings) when failover

occurs (both DR test and real failover). Directions for using the utility are provided in the “SRM Administrator

Guide” in the section titled “Customize IP Properties for a Group of Virtual Machines”. The dr-ip-customizer

utility is a tool that generates a unique customization specification for each VM, and applies that

customization specification to the recovery plan for each VM.

In the design in this document both the primary and DR site are on the same network in a stretched VLAN

scenario.

4.3 NFS STORAGE CONNECTIVITY

In NFS environments the storage network used for connecting to NFS datastores is often a private back end

network that is either physically or logically separated from the virtual machine network. Networks can be

separated on different physical switches, on different physical ports on a shared switch infrastructure using

VLANs, or on the same ports by using VLAN tagging.

In some cases multiple private networks may be configured between an ESX host and an individual NetApp

controller of vFiler for NFS storage. This practice is sometimes used or recommended to increase overall

available throughput between a single ESX host and a single NetApp controller. Some datastores are

accessed on one controller IP, and other datastores are accessed on a different IP on that same controller.

This does not increase throughput to any one particular datastore, but increases overall throughput between

a single ESX host and a single NetApp controller. Configuring multiple networks is only done in

environments where certain Etherchannel configurations are not possible. For more information about NFS

network design for VMware vSphere on NFS environments, see the networking section of the NetApp and

VMware vSphere Storage Best Practices document TR-3749 at http://media.netapp.com/documents/tr-

3749.pdf.