HP 3PAR VMware ESX Implementation Guide

When exporting VLUNs to the VMware ESX host, you should observer the following guidelines:
• New VLUNs that are exported while the host is running may not be registered until a Bus
Rescan is initiated. This may be performed from the VI/vSphere client Management Interface.
Some versions of ESX will automatically scan for newly exported LUNs.
• Disks can be added to a virtual machine with the virtual machine powered up. However, to
remove a disk, the virtual machine may not need to be powered off. Please refer to VMware
documentation for feature support.
• The maximum number of LUNs on a single ESX HBA port is 256, and 256 total LUNs on the
ESX host. Internal devices, such as local hard drives and CD drives, are counted as a LUN in
the ESX host LUN count.
• VLUNs can be created with any LUN number in the range from 0 to 255 (VMware ESX
limitation).
• iSCSI LUNs and FC LUNs are treated as any other LUN on the ESX host. No special
requirements or procedures are needed to use iSCSI LUNs. HP does not recommend or support
same storage LUN being exported on different protocol interfaces, such as exporting to FC
interface on one host and iSCSI on another host, because the timing and error recovery of
the protocols would be different.
• The ESX limitation for the largest LUN that can be utilized by the ESX host is 2047 GB. For
ESXi 5.x, the maximum LUN size is 16 T or 16384 GB.
• Sparse LUN numbering (meaning that LUN numbers can be skipped), is supported by VMware
ESX host. A LUN 0 is not required.
For failover support using the QLogic or Emulex drivers, virtual volumes should be exported down
multiple paths to the host simultaneously. To facilitate this task, create a host definition on the
HP 3PAR StoreServ Storage that includes the WWNs of multiple HBA ports on the host and export
the VLUNs to that host definition.
It has been noted by HP that provisioning several VMs to a smaller number of large LUNs, versus
a single VM per single LUN, provides better overall results. Further examination and explanation
of this recommendation is outlined in 3PAR Utility Storage with VMware vSphere, which is available
on the following website:
3PAR Utility Storage with VMware vSphere
Concerning TPVVs, ESX VMFS-3 and ESX VMFS-5 do not write data to the entire volume at
initialization and it can be used with TPVVs without any configuration changes to VMFS. A further
examination of this subject, recommendations, and limitations are explored in the HP document
3PAR Utility Storage with VMware vSphere.
Creating a VLUN for Export
Creation of a VLUN template enables export of a VV as a VLUN to one or more ESX hosts. There
are four types of VLUN templates:
• port presents - created when only the node:slot:port are specified. The VLUN
is visible to any initiator on the specified port.
• host set - created when a host set is specified. The VLUN is visible to the initiators of
any host that is a member of the set.
• host sees - created when the hostname is specified. The VLUN is visible to the initiators
with any of the host’s WWNs.
• matched set - created when both hostname and node:slot:port are specified.
The VLUN is visible to initiators with the host’s WWNs only on the specified port.
You have the option of exporting the LUNs through the HP 3PAR Management Console or the
HP 3PAR OS CLI.
Exporting LUNs to an ESX Host 77