Quickly stop and start your Windows Azure lab


I needed  way to easily stop and start my different lab setups in Windows Azure. I don’t want to keep running, and pay for, a set of VMs I use maybe once a month. So here is a PowerShell script to stop and start a set of Azure VMs. One important dimension here is the order in which the VMs start (and possibly; shuts down, depending on your setup). Since all IP addresses are dynamically allocated in Windows Azure I had to make sure that my VMs started in a specific order and that the script executed synchronously. That way whatever IP they had when they were provisioned would most likely be assigned to them when they started. Therefore the script includes code to start and stop VMs in the order you specify them in the input file. It also tries to wait until the current VM is fully started or stopped before proceeding with the next one.

Pre-requisites, input file and usage

The input file is really simple. It is a text file with a Cloud Service name and a VM name on each line, separated by a semi-colon, no header:

<cs name>;<vm name>

The VMs in the file will be started in the order they are listed and stopped in the reverse order!

By default, the script looks for a txt file in its execution directory called Control-AzureVMs.txt. If it is not found PowerShell throws an error. You can override this behavior by specifying your own file with VMs to either start or stop.

You must already have your machine configured to use Windows Azure PowerShell and specify your subscription in the script:

Select-AzureSubscription “<your subscription name here>”

Whether you want to start or stop a set of VMs is controlled by a script parameter. You use either Stop or Start. Optionally you can add your own txt file with VMs after the Start/Stop parameter.

Usage with the default input file:

Control-AzureVMs.ps1 Stop

Control-AzureVMs.ps1 Start

Usage with the custom input file:

Control-AzureVMs.ps1 Stop MySetOfVms.txt

The code

Here is the code. I can think of all sorts of improvements, but I needed this quickly so that will have to wait. Error checking is pretty much non-existent at this point so use at your own risk. I accept no responsibility whatsoever.

UPDATE: With the release of the Windows Azure PowerShell module v0.7.3 you can now create DHCP reservations for your VMs that will persist when the machine is deallocated. Check out Get-AzureStaticVNetIP, Set-AzureStaticVNetIP, Remove-AzureStaticVNetIP and Test-AzureStaticVNetIP.

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