Maintenance mode on ESX hosts is great. As long as DRS is set to automatic and VMotion is working, all of the VM’s will be evacuated from the host. However, I always seem to run into one VM that still has a CDROM drive connected to it. This causes the VMotion to stop until the CDROM drive is disconnected.

Since, this happened quite frequently, I decided to do maintenance mode through PowerShell to automate the process . The below script will:

• Search for any VM’s that have CDROM’s connected
• Disconnect the CDROM’s from said VM’s
• VMotion the VM’s to the remaining ESX hosts (there is no way that I know of to automatically VMotion the VM’s by just putting the host into maintenance mode using PowerShell)
• Put the target host into maintenance mode

A special thanks goes to Steve Beaver. His post “Working with Maintenance Mode in PowerShell” helped me figure out the automatic VMotion to the remaining hosts.

So, here it is:

# Name: esx-maintenance-prep.ps1
# Purpose: Disconnects all CDROM Drives on VM's from a chosen host. It will VMotion the
#          VM's on that host. Then, it will put the host into maintenance mode.
#
# Created: 09/11/2009
# Author: Harley Stagner
# Version: 1
#
# TODO:
#  -Wrap work into functions
#  -Use if statement to account for VM's that are powered off
################################################################

#Connect to your vCenter Server
Connect-VIServer

Write-Host "Choose your server from the list below:"

# Set up variables for the Host Selection
$colESX = Get-VMHost
$selectionNumber = 0

#HashTable
$colHostSelection = @{} 

#Array
$colSelection = @() 

# Create the menu choices for the hosts
$colESX | sort Name | ForEach-Object {

	$selectionNumber = $selectionNumber + 1

	$colHostSelection.Add("$selectionNumber", "$_")

	Write-Host "$selectionNumber - $_"
}

# Needed to match the option for the switch statement
$colHostSelection.Keys | ForEach-Object{
$colSelection += $_
}

# Have the VM Admin make the host selection
$VMHostSelection = Read-Host "Please choose an option between" $colSelection[0] "and" $colSelection[-1]
$VMHost = $colHostSelection[$VMHostSelection]

# Switch statement to get the appropriate host to put into maintenance mode.
switch ($colSelection[0]..$colSelection[-1]){

	{$_ -eq $VMHostSelection} {

# Disconnect the CDRom Drives from the VM's.
		Get-VMHost $VMHost | Get-VM | Get-CDDrive | Set-CDDrive -Connected $false -Confirm:$false

			ForEach ($ESX in $colESX){

				If ($ESX -cnotmatch $VMHost){

# vMotion the VM's to the other hosts in the cluster.
          			Get-VMHost -Name $VMHost | Get-VM | Move-VM -Destination (Get-VMHost $ESX)
    			}
			}

# Put the chosen host into Maintenance Mode.
	Get-VMHost -Name $VMHost | Set-VMHost -State Maintenance | ForEach-Object { "Entering maintenance mode on '" + $VMHost + "'"} ; continue
	}
}

Disconnect-VIServer -Confirm:$False

#END SCRIPT#

As you can see, I still have a couple items in my to do list for this script. However, it is very useable as it stands.