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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Using third-party multi-pathing plug-ins (MPPs)
vSphere 4.x/5x allow third-party storage vendors to develop proprietary PSP, SATP, or MPP plug-ins (or MEMs).
These third-party MEMs are offered to customers at an incremental license cost and also require enterprise VMware
licensing.
The EVA array was designed to provide optimal performance and functionality using native VMware multi-pathing plug-ins,
saving you the extra work and expense associated with proprietary plug-ins. When used, configured and tuned
appropriately, native plug-ins can significantly reduce configuration time and provide enhanced performance in most
environments at zero incremental cost, while keeping the solution simplified.
Upgrading EVA microcode
An online upgrade of EVA microcode is supported with vSphere 4.x/5.x.
When performing such upgrades it is critical to follow the general EVA Online Firmware Upgrade (OLFU) guidelines defined in
the OLFU best practices guide
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.
From a vSphere 4.x/5.x perspective, VMs using RDM Vdisks are more susceptible to issues resulting from an OLFU. It is
important to ensure that the SCSI disk timeout for all VMs is set to a minimum of 60 seconds, or higher (60 – 90 seconds) in
a larger environment.
Guidelines are provided for setting the SCSI disk timeout for Microsoft Windows and Linux VMs.
Setting the timeout for Windows VM
For a VM running Windows Server 2003
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or earlier, change the value of the
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Disk/TimeoutValue registry setting to 3c (that is, 60 expressed
in hexadecimal form).
A reboot is required for this change to take effect.
Setting the timeout for Linux VMs
Use one of the following commands to verify that the SCSI disk timeout has been set to a minimum of 60 seconds:
cat /sys/bus/scsi/devices/W:X:Y:Z/timeout
or
cat /sys/block/sdX/device/timeout
If required, set the value to 60 using one of the following commands:
echo 60 > /sys/bus/scsi/devices/W:X:Y:Z
or
echo 60 | cat /sys/block/sdX/device/timeout
where W:X:Y:Z or sdX is the desired device.
No reboot is required for these changes to take effect.
Overview of vSphere 4.x/5.x storage
vSphere 4.x/5.x support VMware Virtual Machine File System (VMFS), RDM, and Network File System (NFS) datastores, each
of which can deliver benefits in a particular environment. This section provides information for the following topics:
• Using VMFS
• Using RDM
• Comparing supported features
• Implementing a naming convention
• Sizing the vSphere cluster
• Aligning partitions
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See http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01921588/c01921588.pdf
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In Windows Server 2008, the SCSI timeout defaults to 60 seconds.