User guide

Technical white paper | HP Enterprise Virtual Array Storage and VMware vSphere 4.x and 5.x configuration best practices
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The advantages of this naming convention are as follows:
• Simple
• Synchronizes EVA and vSphere naming
• Independent of any unique array or Vdisk properties
• Does not break due to replication or Storage vMotion
• Uniqueness automatically ensured by EVA
However, there are challenges associated with the naming convention, including the following:
• Inability to quickly match the array Vdisk number only using the Vdisk name
• Cross-reference matrix required for information such as Vdisk ID and array
Both of the above challenges can be addressed by deploying the HP Insight Control Storage Module for vCenter plug-in.
Best practice for naming datastores
• When naming a datastore, utilize the same name used in Command View when the Vdisk was created.
• Use simple, consistent names for your datastores – in the future, you may need to add vSphere hosts to the cluster.
Sizing the vSphere cluster
Knowing how many vSphere hosts can be supported per Vdisk will enhance your ability to manage the cluster
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Monitor resource utilization to recognize VMs that are I/O-intensive. Often, high I/O requirements will lower your overall host
count.
Best practice for using Vdisk IDs
• To make it easier to manage the cluster and SAN, use the same Vdisk ID for all vSphere hosts in the same cluster.
Aligning partitions
In a vSphere environment, partitions on VM data disks must be aligned with disks on the EVA array; however, the EVA array
has no alignment requirements. See the VMware vStorage API for Array Integration section below for VAAI specific
alignment considerations and best practices.
Aligning Vdisk and VMFS partitions
The array is a virtualized storage system that is managed by Command View. When you use Command View to create a
Vdisk to present to a supported host, the host mode you specify ensures that the Vdisk is appropriately aligned for the file
system you plan to mount.
When you present a Vdisk to a host, you can use your favorite secure shell (ssh) client to login to your vSphere host and
view the configuration of the presented Vdisk; you can then format the Vdisk with a VMFS filesystem. Using the vSphere
client to create the VMFS filesystem automatically aligns the VMFS filesystem partition with the underlying Vdisk.
Aligning VM operating system partitions
IMPORTANT
If you are using Microsoft Windows Vista®, Windows 7, or Windows Server 2008, you do not need to align partitions. These
operating systems correctly align the partition at the time you create the VMDK.
At some stage of your deployment, you may need to align the partitions for certain VM operating systems with the VMDK to
avoid performance degradation in your VM or application.
For EVA arrays, HP recommends creating all your VMDK files via the vSphere client and verifying that each Vdisk is
appropriately aligned; other storage systems may be different.
If you are using Storage vMotion to move your datastores, consult the appropriate storage vendor to ensure your VMFS
partitions or VMDK files are correctly aligned to disk.
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The maximum number of Vdisks that can be connected to a vSphere cluster is 256.