Powershell ESX Lun Balance script

Back again from a long break. I found out that many of the unix based scripts are going to be obsolete within a couple of month. so here is a powershell version of my earlier published script. Thanks to Justin Emerson, http://vmjunkie.wordpress.com/ for the basics of this script. a little copy paste and some mods.

# Cluster/host lun balance script
# Allan Christiansen http://doitsmarter.blogspot.com/

Write-Host "This script will modify the policy of all your shared LUNs on all ESX Servers" -ForegroundColor Cyan

Write-Host "in a Cluster to Fixed and select a preferred path in a round-robin fashion." -ForegroundColor Cyan

#

if ($args.Length -lt 2) {

Write-Host "usage: -c or -s "

exit 1

} else {

if ($args[0] -eq "-c") { $VMHosts = Get-Cluster $args[1] | Get-VMHost }

if ($args[0] -eq "-s") { $VMHosts = Get-VMHost $args[1] }

}

Write-Host "Modifiying ESX hosts:" $VMHosts

foreach ($VMHost in $VMHosts)

{

$luns = $VMHost|get-scsilun -luntype disk| where-object {$_.ConsoleDeviceName -like "/vmfs/devices/disks/vml*"}| Where-object {$_.CanonicalName -notlike "vmhba32*"} |Sort-Object CanonicalName

$firstLUNPaths = Get-ScsiLunPath $luns[0]

$numPaths = $firstLUNPaths.Length

$count = 0

foreach ($lun in $luns)

{

"count   : $count"

"numpath : $numPaths"

$lun.CanonicalName

if ($count -ge $numPaths) { $count = 0 }

$paths = Get-ScsiLunPath -ScsiLun $lun

$paths

$lun|Set-ScsiLun -MultipathPolicy Fixed -PreferredPath $paths[$count]

$count += 1

# Sleep for some seconds as some arrays dont like doing this too fast. and with running vm's its .....

Start-Sleep -Seconds 3

}

}

# Thanks to Justin Emerson, http://vmjunkie.wordpress.com for the basics of this.