FlashArray Host Personalities for ESXi

When Pure Storage released Purity 5.1 for the FlashArray they introduced a new host feature called Host Personality. Host Personalities offer a way to customize how the FlashArray presents storage to the physical host. Today Pure offers 5 types of Host Personalities:

  • ESXi
  • Hitachi VSP
  • HP-UX
  • Oracle VM Server
  • VMS

This post specifically focuses on what’s provided with the ESXi host personality and how to set this using PowerShell, VMware PowerCLI and the Pure Storage PowerShell SDK.

Benefits of the ESXi Personality

Before going into the specific enhancements I think it is important to point out that you should set the personality regardless if you need these enhancements or not. As Pure Storage continues to evolve Purity there likely will be other enhancements added to the personality, and by having it set you can avoid a maintenance window later to set the personality.

The ESXi personality on the FlashArray provides two major enhancements:

  1. Changes the LUN addressing from flat LUN ID to peripheral LUN ID. This change allows ESXi to now see LUNs that are presented with an ID of 256 or higher. When you set the host personality to ESXi in the FlashArray the hosts will now be able to use the maximum number of LUN IDs as documented in the Config Maximums document. This is applicable for both Active Cluster enabled environments or normal environments.
  2. Issue a Permanent Device Loss (PDL) whenever an Active Cluster pod marks itself offline due to the loss of a mediator. This is a critical enhancement needed for vSphere clusters. Without this setting enabled, when a Pod goes offline, the host is not notified and a restart of the VM isn’t executed. With the ESXi personality enabled the FlashArray will properly send a PDL sense code to the ESXi hosts so they know the path is gone, is not coming back, and they need to execute HA failovers.

Configuring ESXi Host Personality

The Pure Storage documentation covers how to set the Host Personality via the GUI, so I’m not going to cover that here. Since I like to automate whenever possible, I assembled a PowerShell script to handle this process.

Please Note: It is critical that the hosts are not servicing VMs when you set this. When the Personality is set, the ESXi host will temporarily lose connectivity to the array. The script I provided below will set

First you will need the Pure Storage PowerShell SDK and the VMware PowerCLI modules. To install these execute the following from a PowerShell prompt:

Find-module PureStoragePowerShellSDK,VMware.PowerCLI | Install-Module

Here’s the full script. I’ll explain what’s happening below.

#Requires -Modules PureStoragePowerShellSDK,VMware.VimAutomation.Core
    Configure the ESXi Host Personality on a FlashArray

    This script will place a list of ESXi hosts into Maintennace Mode and then
    set the appropriate personality flags on one or more FlashArrays.

    .PARAMETER FlashArrays
    One or more FlashArray IPs or host names to check for ESXi host objects.

    .PARAMETER vCenter
    FQDN of the vCenter server used to obtain ESXi host information from.

    List of ESXi hosts to place into maintenance mode and set the Personality
    for.  If ommitted, all hosts found in the connected vCenter will be operated
    Note: This must match the name of the host in vCenter exactly.

    .\Set-ESXiPersonality.ps1 -FlashArray FlashArray1.contoso.com,FlashArray2.contoso.com -vCenter test-vcenter.contoso.com 

    Author: Steve Sumichrast <ssumichrast@sumistev.com>
    Version: 1.1 
    1.1 - Added support for multiple FlashArrays and to target to specific VM
    1.0 - First version of script

    [Parameter(Mandatory = $true)]
    [Parameter(Mandatory = $true)]

# Attempt to connect to the FlashArray(s)
try {
    $Credentials = Get-Credential -Message "Login to FlashArray"
    $pfa = $FlashArrays | Foreach-Object -Process {
        New-PfaArray -EndPoint $_ -Credentials $Credentials -IgnoreCertificateError
    Write-Host "Successfully connected to the following FlashArrays:"
    $pfa | ForEach-Object -Process {
        Write-Host " $($_.EndPoint)"
catch {
    throw "Failed to log in to FlashArrays."

# Attempt to connect to vCenter
try {
    $vCenterObj = Connect-VIServer -Server $vCenter
    Write-Host "Successfully connected to vCenter Server $($vCenter)"
catch {
    throw "Failed to connect to vCenter Server $($vCenter)."

# Obtain VMHosts
try {
    if (!$ESXiHosts) {
        $ESXiHosts = Get-VMHost -Server $vCenter
    $VMhosts = Get-VMhost $ESXiHosts
    Write-Host "Found the following ESXi hosts to operate on:"
    $VMhosts | Foreach-Object -Process {
        Write-Host " $($_.name)"
catch {
    throw "Failed to obtain ESXi hosts."

# Set the Host Personality on the FlashArrays
try {
    $VMhosts | Foreach-Object -Process {
        Write-host "Configuring $($_.name)."
        Write-host " Placing $($_.name) into Maintenance Mode"
        $_ | Set-VMHost -State Maintenance

        Write-Host " Obtaining WWPN for host"
        # Obtain a WWPN from the HBA to match it up to Purity. Using HBA
        # identifiers since they have to match exactly between ESXi and Purity,
        # unlike the Name field.
        #Note that the 0:X is to convert the output to Hex.
        $wwpn = $_ | Get-VMHostHBA -Type FibreChannel | Select-Object -First 1 @{N = "WWPN"; E = {"{0:X}" -f $_.PortWorldWideName}} | Select-Object -ExpandProperty WWPN

        # Set the Purity personality for each FlashArray we're connected to.
        $pfa | Foreach-Object -Process {
            Write-Host " Setting personality for $($PFAHost.Name) on $($_.Endpoint)"
            $PFAHost = Get-PfaHosts -Array $_ -Filter "wwn = '$($wwpn)'"
            Set-PfaHostPersonality -Array $_ -Name $PFAHost.Name -Personality esxi

        Write-Host " Exiting Maintenance Mode for $($_.name)"
        $_ | Set-VMhost -State Connected
        Write-Host " $($_.Name) configured successfully."
        Write-Host ""
catch {
    throw "Failed to configure personalities."

# Disconnect from vCenter
Disconnect-VIServer $vCenterObj -Confirm:$false

Lines 45-68
In this block we are just connecting to the Pure Storage FlashArray and to the respective VMware vCenter server to obtain ESXi host information.

Line 70 – 84
Here the script is gathering the matching ESXi host objects so we can iterate over them and obtain HBA data later.

Line 86 – 116
This is the heavy lifting in the script. Here the script processes each ESXi host that we found in the above section. For each host we place it into Maintenance Mode, and wait for that to complete. Once the host enters maintenance mode (Line 91) we then proceed to find a WWPN from the first FibreChannel HBA located on this ESXi server (Line 99). Note that here we have to convert the output from PowerCLI to Hex so that we can match it up in the FlashArray. Lines 102 through 106 are a loop for each FlashArray specified (in case the host is connected to more than one FlashArray). We use the PFA object we obtained in the first section, get a list of hosts on that array that match the filter (Line 104), and then we set that host object to use the personality “esxi”. Note: It must be specified exactly that way — this field is case sensitive. Afterwards, we simply exit maintenance mode for the host (line 109) and then we repeat this process for any remaining ESXi hosts.

For additional information on Host Personalities, I’d recommend checking out Cody Hosterman’s blog post on 6.7 and Flat LUN IDs.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.