DRSRule – a DRS rules and groups module

One of the nice vSphere features is the ability to define DRS rules.

The feature allows a vSphere administrator to control the placement of virtual machines in a vSphere cluster. There are the VM to VM affinity and anti-affinity rules, and the newer VM to VMHost rules. With the VM to VMHost rules, vSphere introduced the concept of VM and VMHost groups, and the ability to have rules that are a requirement (‘shall’) or a preference (‘should’).

In a recent VMTN PowerCLI community thread a PowerCLI user had a query about exporting and importing DRS rules and groups. At that point Matt Boren and myself developed the idea to provide a PowerShell module. The PowerShell module, which we named DRSRule, provides all the functions we deemed useful for working with DRS rules and groups. And yes, the module includes an export and an import cmdlet !

Matt Boren, famous for the high quality posts on his vNugglets blog, and myself, started working on the module, and after some late evenings and long weekends, we now have a first version we want to make public.

There are already many blogposts on the subject of DRS rules and groups. Including some excellent PowerCLI posts. The first one that springs to mind is Arnim‘s excellent Managing VMware DRS rules using PowerCLI.

And don’t forget to read Matt’s post on the DRSRule module as well.

To get you on your way with the DRSRule module, Matt and myself compiled the following introductory text.

Why the DRSRule module?

The core PowerCLI from VMware allows for many of the DRS rule operations that one might want to perform.  There have been questions over the years in the VMware Communities PowerCLI forum about how to export DRS rules and groups, and, on how to then import such items.

While there are several posts on the web about how to get/export such things, importing/recreating DRS rules/groups from such exported data has not received much focus.  This was the spark for this DRSRule module:  to allow for easy export/import of such rules/groups.  As part of making a module to handle these actions, other cmdlets were born, like the Get-/New-/Remove-/Set-* cmdlet sets for DRS VM groups and VMHost groups, along with sets for DRS VM to VM rules and VM to VMHost rules.

How to use the DRSRule module?

The DRSRule module comes with an about_DRSRule.
Once the module is installed, use that help topic to get a general introduction to the use of the DRSRule module:

How to get the DRSRule module ?

The source for this PowerShell module is hosted on GitHub.com.
The repository is managed by the GitHub organization PowerCLIGoodies, and in there is the DRSRule repository itself.

There are a couple of ways to get the module, and use it in your PowerShell session:

Automated

Via a script

Use a PowerShell script to perform the download and the extract.
The script is included in the repository as file DownloadLatest.ps1.

Via PsGet

If you have the PsGet module loaded in your PowerShell session, then installing this DRSRule module is as simple as updating PsGet and then installing DRSRule:

Manual

Grab the latest version from the GitHub repository.
Extract the content to a suitable folder.

You can go for the Modules folder linked to the Windows account you are using. To find this path, run:

Or you can select any other folder.

Either way you will end up with a folder named [pathToModule]\DRSRule, in which the PowerShell files for the DRSRule module reside.

Then, load the DRSRule module into your session.

If you selected one of the folders in $env:PSModulePath (your PSModule path), you can do this with

If you picked another folder, you should use the full path to the folder that contains the module’s files, like:

Please also read the note below about using Unblock-File, since this module is not Authenticode signed.

Note on Unblock-File

Since there is no Authenticode certificate supplied for this module, and, assuming that one’s PowerShell ExecutionPolicy is at least RemoteSigned, below is a quick/easy way to unblock files.  But, this should only be done when you trust the code in the files that you are unblocking — inspecting the files is for your own good.

The DRSRule module was set up as community resource, so we are hoping to see your comments, suggestions and code.

Enjoy !