#PURPOSE: SET ODD LUN's PREFERRED PATH TO vmhba1 AND EVEN LUN's PREFERRED PATH TO vmhba2
# AND SET THE POLICY TO FIXED

#FORCE TO LOAD VMWARE POWERSHELL PLUGIN
[Reflection.Assembly]::LoadWithPartialName("vmware.vim")

#ON ERROR CONTINUE
$erroractionpreference = "SilentlyContinue"


#VARIABLES
$policy = new-object VMware.Vim.HostMultipathInfoFixedLogicalUnitPolicy
$policy.policy = "fixed"
$UNEVEN = "vmhba1"
$EVEN = "vmhba2"
$VCHOST = "localhost"


#CONNECT TO THE SERVER
Get-viserver -Server $VCHOST

#GET ALL THE ESX HOST
$ALL_ESXHOSTS = get-vmhost | where { $_.State -eq "Connected" }

# LOOP THROUGH THE ARRAY
foreach ($i in $ALL_ESXHOSTS)
				{ 
					$ESXHOST = $i.name
					Get-VMhost $ESXHOST
					
					#ERROR HANDLING
					if (! $?)
					{
						write-host "ERROR CONNECTING TO HOST: $ESXHOST [ERROR]" -ForeGroundColor Red
					}
					
					else
					
					{
						write-host "CONNECTED TO HOST: $ESXHOST [OK]" -ForegroundColor Green
					}	
					
					
						#GET THE STORAGE PATHS
						$GET_HOST = Get-VMhost $ESXHOST
						$HOST_VIEW = Get-View $GET_HOST.id
						$STORAGESYSTEM = get-view $HOST_VIEW.ConfigManager.StorageSystem


							#LOOP THROUGH THE LUN'S ADD THEM TO THE ARRAY
							$ARRLUN = $STORAGESYSTEM.StorageDeviceInfo.MultipathInfo.lun | where { $_.Path.length -gt 1 }
							
								if ( $ARRLUN -eq $null )
									{
										
										write-host "ESXHOST: $ESXHOST HAS NO LUNS [ERROR]" -ForeGroundColor Red
									}
									
								else
									{
							
																#LOOP THROUGH LUN's
																foreach ($LUN in $ARRLUN)
									
																	#CHECK IF THE LUN IS EVEN OR UNEVEN AND SET THE POLICY
																	{ $CHECK_LUN = $LUN.id.split(':')
																	$CHECK_LUNID = $CHECK_LUN[2]
									
																		if($CHECK_LUNID -band 1) 
																			{ Write-Host LUN: $LUN.id = "ODD LUN NUMBER" -ForegroundColor Blue
																				
																				#GET THE PROPER VMHBA
																				$GET_VMHBA = $LUN.Path | where {$_.Name -match $UNEVEN}
																				$policy.prefer = $GET_VMHBA.Name
																				
																				#SET THE NEW PATH + POLICY
																				$NEW = "NEW PATH FOR LUN:" + " " + $LUN.id + " " + "IS:" + " " + $policy.prefer
																				$storageSystem.SetMultipathLunPolicy($LUN.id, $policy)
																				
																					#ERROR HANDLING
																					if (! $?)
																					{
																					
																						write-host $NEW "[ERROR]" -ForegroundColor Red
																					}
																					
																					else
																					
																					{	
																					
																						write-host $NEW "[OK]" -ForegroundColor Green
																					
																						
																					}
																				
																				
																			}
																					
																		else 
																			{  Write-Host LUN: $LUN.id = "EVEN LUN NUMBER" -ForegroundColor Blue
																				
																				#GET THE PROPER VMHBA
																				$GET_VMHBA = $LUN.Path | where {$_.Name -match $EVEN}
																				$policy.prefer = $GET_VMHBA.Name
																				
																				#SET THE NEW PATH + POLICY
																				$NEW = "NEW PATH FOR LUN:" + " " + $LUN.id + " " + "IS:" + " " + $policy.prefer
																				$storageSystem.SetMultipathLunPolicy($LUN.id, $policy)
																				
																					#ERROR HANDLING
																					if (! $?)
																					{
																					
																						write-host $NEW "[ERROR]" -ForegroundColor Red
																					}
																					
																					else
																					
																					{	
																						write-host $NEW "[OK]" -ForegroundColor Green
																					}
																			}
																	}
									}
									
									}