ESXi natively supports multipath I/O (MPIO). The following MPIO policies are available:
- Most Recently Used (MRU)
Pure Storage recommends Round-Robin multipathing policy.
Configuring Round Robin (VMware) MPIO Policy using vSphere Web Client
- Select the Datastore Tab -> Manage -> Settings -> Connectivity and Multipathing -> Select Host->Edit Multipathing...
- Change the policy to Round-Robin
- Click OK
Configuring Round Robin (VMware) policy using Pure Storage Management Plugin for vSphere
The Pure Storage Management Plugin is capable of setting the round-robin policy on multiple objects such as datastores, hosts, cluster (all hosts in the cluster), and datacenters (all hosts in selected datacenter.
In the vSphere Web Client
- Select the object to be configure and right-click it or choose "Actions" in the top bar
- Select Configure Multipathing -> Apply
Configuring Round Robin (VMware) policy using command line and setting the I/O operation limit
The I/O operation limit defines the number of I/O operations required to trigger the change of an active path.
Pure Storage recommends I/O operation limit of 1.
Execute as root the following command on all ESXi hosts:
esxcli storage nmp satp rule add -s "VMW_SATP_ALUA" -V "PURE" -M "FlashArray" -P "VMW_PSP_RR" -O "iops=1"
Setting satp rule will automatically apply Round Robin (VMware) policy for all newly created volumes. The policy for existing volumes will be applied after the host reboot.
For additional information refer to VMware vSphere Best Practices Guide for the Pure Storage® FlashArray