A very common practice when setting up SAN storage on a VMWare cluster is to configure the storage path policy to be set to "Round Robin" to properly benefit from MPIO in addition to standard failover. However, if the cluster consists of many nodes or there are many volumes, this can take up quite a lot of time if you configure this using the (Web)GUI. A better way to adjust the setting for the entire cluster is through PowerCLI.

The one-liner:

Get-VMHost <Cluster-or-Host> | Get-ScsiLun -LunType "disk" | Where {$_.MultipathPolicy -ne "RoundRobin"} | Set-ScsiLun -MultipathPolicy RoundRobin

The cmdlet selects a cluster or host, gets all LUNs which are of   ...