Tuesday, July 9, 2013

View PowerCli Script: Automate linked clone master (base image) OS update and recompose

I believe this is one of the nightmare of View Administrators. When you have a lot of View Pool, the effort to maintain the master image is going to be tough.

While you can use ThinApp to simplify the application management, there are some occassion you cannot use ThinApp, you may have to manually update OS patches or application in the master image and do recompose to keep your link clone updated.

This process is tedious and I have two scripts to automate the OS patches update.
  1. Script to trigger Windows Update automatically on all master (or base image) that need update.
  2. Script to create a new snapshot, delete the old snapshots except the last snapshot and trigger recompose of the link clone pool.
The first script should be run first and let it run for a few hours to ensure all installation and reboot are completed before we go to step 2 to generate snapshot and link clone.

Script to trigger Windows Update automatically on all master (or base image) that need update.

The first script (OSupdate.ps1) is create to run the windows update script on all VM required.

Please visit my previous post and save that files (update.bat and wua.vbs) in the same directory as OSupdate.ps1


To run the OSupdate.ps1 script, we have the following assumption.
  • All VM to be updated by the script has the same username and password with local administrator right. If there are a few different username/password, you could group those VMs with same username/password.
  • During the creation of those master image, the Windows update agent should be updated to at least 7.4.7600.226 and XP should be at least SP3.
  • All VMs should be able to access Windows Update server in Internet or the agent should be configured to pointing to any internal WSUS server.
  • All VMs are in the same folder
Basically, this script will be go through all VM in the folder specified, copy the update.bat and wua.vbs to c:\ and then run the update.bat. If the VM is powered off, it will be powered on by the script automatically.

Since the windows update are different every month, it may take a very long time for your script to download and install all patches, therefore, please make sure you have enough time to run this before you do the link clone recompose.

Here's the OSupdate.ps1 script, there are a few parameters here..
  1. Vcenter - that's the Vcenter address
  2. Folder - that's the folder contains all VMs to be updated.
  3. Admin - That's the username with local admin right on the VM operating system.
  4. Password - That's the password of the account with local admin right on the VM operating system. 

./OSupdate.ps1 -vcenter VCENTER.DOMAIN.COM -folder "VMFolders" -admin Administrator -password Password

------------Start of OSupdate.ps1--------------

param ($vcenter, $folder, $admin, $password)

connect-viserver -server $vcenter
$VM = Get-Folder $folder | Get-VM

foreach ($v in $VM) {

if ($v.powerstate -eq "PoweredOff") {
start-VM -VM $v
start-sleep -s 180


Copy-VMGuestFile -Source update.bat -Destination c:\ -VM $v -LocalToGuest -GuestUser $admin -GuestPassword $password

Copy-VMGuestFile -Source wua.vbs -Destination c:\ -VM $v -LocalToGuest -GuestUser $admin -GuestPassword $password

Invoke-VMScript "c:\update.bat" -vm $v -GuestUser $admin -GuestPassword $password -ScriptType "bat"


--------------End of OSupdate.ps1--------------

 Script to recompose Link clone pool

The second script is to recompose the link clone pool.

Here's the parameter of the script
  1. pool_id - the ID of the link clone pool
  2. parentvm - the name of the VM of the master image
  3. delay - the number of minutes delay you wants the recompose to happen (this allows you to run this script for all VMs at the same time but the actual recompose can happens at different time to avoid IOPS storm)
  4. vcenteraddy - the full address of the Vcenter
  5. folder - the VM folder name of the master image


./recompose.ps1 -pool_id "VM1" -vcenter VCENTER.DOMAIN.COM -folder "VMFolders" -parentvm "VMDesktop" -delay 10

------------Start of recompose.ps1-------------

param ($pool_id, $parentvm, $delay, $vcenteraddy, $folder) 

#User set variables

#Connect to vcenter and set some other variables
Connect-VIServer $vcenteraddy
Get-Datacenter | set-Variable -name datacenter

write-host $datacenter
$VM = Get-Folder $folder | Get-VM -Name $parentvm

$p = $parentvm
$Snap = Get-Snapshot -VM $VM -WarningAction SilentlyContinue | Sort-Object Created
$count = 0
foreach ($s in $Snap){
$count = $count + 1
Write-host $count
Write-host $s.name

foreach ($s in $Snap){
if ($count -gt 1) {
$k = " Removing " + $s.name
Write-host $k
Write-host $count
Remove-Snapshot -Snapshot $s -confirm:$false

$count = $count - 1
Write-Host $count


$p = get-date.Year + get-date.Month + get-date.Day + get-date.Hour + get-date.minute + get-date.second

Write-Host $p
Get-VM $VM | New-Snapshot -Name $p
Write-Host "New Snapshot created"

$snapshots = Get-Snapshot -VM $VM -WarningAction SilentlyContinue | select VM, Name, @{Name="Age";Expression={((Get-Date)-$_.Created).Hours}} | Sort-Object Age
$parentsnapshotpath = ""
foreach ($s in $snapshots){
$parentsnapshotpath = "/" + $s.Name + $parentsnapshotpath
write-host $parentsnapshotpath

get-composerdomain | Get-DesktopVM -pool_id $pool_id | Send-LinkedCloneRecompose -schedule ((Get-Date).AddMinutes($delay)) -parentvmpath /$datacenter/vm/$folder/$parentvm -parentsnapshotpath $parentsnapshotpath -forceLogoff:$true -stopOnError:$true

update-automaticlinkedclonepool -pool_id $pool_id -parentSnapshotPath $parentsnapshotpath
Write-Host "Pool recomposed sucessfully."

-------------End of Recompose.ps1-------------

Here's some of my reference

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