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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Implementing multi-pathing
Since vSphere 4.x and 5.x are ALUA-compliant, their implementation of multi-pathing is less complex and delivers higher
levels of reliability than ESX 3.5 or earlier.
Setting up multi-pathing only requires the following steps:
• Configure the Vdisk
• Select the controller access policy at the EVA
• Power on/reboot all vSphere 4.x/5.x servers or perform a rescan
Following the boot or rescan, vSphere 4.x detects the optimal access paths and, if MRU, round robin I/O or Fixed_AP path
policy has been selected, gives optimal paths the priority for issuing I/Os.
Figure 14 shows a typical multi-pathing implementation using vSphere 4.x/5.x.
Figure 14. EVA connectivity with vSphere 4.x/5.x
All I/Os to Vdisks 1 – 4 are routed through one or more ports on Controller 1 and through Paths  and/or , regardless of
the HBA that originates the I/O. Similarly, all I/Os to Vdisks 5 – 7 are routed to Controller 2 through Paths  and/,
regardless of the originating HBA.
The vSphere 4.x/5.x implementation yields much higher system resource utilization and throughput and, most importantly,
delivers a balanced system out of the box, with no intricate configuration required.