User guide

Technical white paper | HP Enterprise Virtual Array Storage and VMware vSphere 4.x and 5.x configuration best practices

Best practice for configuring PSP in a multi-vendor SAN

• vSphere 4: When using vSphere 4 in a multi-vendor, ALUA-compliant SAN environment, configure the default PSP for the

VMW_SATP_ALUA SATP to the recommended setting for the predominant array type or to the recommended setting for

the array type with the most Vdisks provisioned for vSphere access.

• vSphere 4.1/5.x: Create a SATP rule entry for each storage array with the desired attributes.

Using Microsoft clustering

At the time of writing, VMware does not support round robin I/O path policy in conjunction with VMs clustered via Microsoft

Cluster Server (MSCS). Thus, HP recommends setting all VMware Raw Device Mapping (RDM) Vdisks used by an MSCS cluster

to utilize MRU as the preferred I/O path policy.

Since most MSCS cluster deployments utilize several logical units, you should configure the path policy for these Vdisks

manually.

Best practice for configuring MSCS cluster Vdisks

• MSCS cluster Vdisks should be configured to use the MRU I/O path policy. Since the recommended default setting for all

EVA Vdisks is round robin, you must manually configure these Vdisks to MRU.

Toggling I/O path policy options

Once configured, avoid toggling the I/O path policy for Vdisks using round robin policy. When I/O path policy is changed from

round robin to any other (fixed or MRU), either through vCenter or a CLI, all round robin advanced configuration settings are

lost. The next time you set round robin policy for that device, you must manually reset these settings.

Using data replication groups

The HP Continuous Access EVA software allows data to be replicated between two or more EVA arrays, either synchronously

or asynchronously.

Continuous Access EVA supports various interconnection technologies such as Fibre Channel or Fibre Channel over IP (FCIP).

A DR group is the largest replication object within Continuous Access EVA and is comprised of replicated Vdisks (copy sets),

as shown in Figure 18.

Figure 18. Relationship between Vdisks and the DR group

Just like a Vdisk, a DR group is managed through one controller or the other; in turn, this controller must manage all Vdisks

within the particular DR group. Thus, when a Vdisk is added to an existing DR group, its optimal controller is the one

currently managing the DR group.

Since the inheritance of controllers can impact the overall balance of Vdisk access, you should ensure that DR groups are

spread across both controllers.

Best practice for managing controllers for DR groups

• Ensure that DR groups are spread between the controllers so as to maintain an adequate balance.

Disk Group

DR Group

Vdisk