Setting the FlashArray “ESXi” Host Personality

In Purity 5.1 and later, there is a new Host Personality in Purity type for VMware ESXi hosts. Changing a host personality on a FlashArray host object causes the array to change some of its behavior for specific host types.

In general, Purity automatically behaves correctly without specific configuration changes. However, due to a variety of host types supported and varying requirements, you must perform a manual configuration.

In Purity 5.1, we recommend enabling the “ESXi” host personality for all host objects that represent ESXi hosts.

The ESXi personality does the following as of Purity 5.1.0:

• It makes the FlashArray issue a Permanent Device Loss SCSI sense response to ESXi when a pod goes offline due to a mediator loss. If this is not set, no response is sent, and vSphere HA does not detect the failure properly. It will not restart VMs running on the failed hosts.
• ESXi uses peripheral LUN IDs instead of flat LUN IDs—this changes how ESXi views any LUN ID on the FlashArray above 255. Since ESXi does not properly interpret flat LUN IDs, it sees LUN ID higher than 255 to be 16,383 higher than it should be (256 is seen as 16,639), which is outside of the supported range of ESXi. Setting the ESXi personality on the FlashArray for a given host switches the FlashArray LUN methodology to peripheral, allowing ESXi to see LUN IDs higher than 255.

While this personality change is currently only relevant for specific ActiveCluster environments and/or environments that want to use higher-than-255 LUN IDs, we recommend setting this on all ESXi host objects.

The ESXi host personality can be set through the FlashArray GUI, the CLI, or REST.