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 !
Continue reading DRSRule – a DRS rules and groups module
In a previous post in this series (see PowerCLI & vSphere statistics – Part 2 – Come together), I showed the usefulness of the Group-Object cmdlet when working with statistical data. The script in that post grouped data samples for each hour together, which made it much easier to calculate the hourly average. With the Group-Object cmdlet you avoid numerous nested if- or switch-statements.
And best of all, you don’t have to code the grouping yourself, it was all done for you by the PowerShell Team.
So make sure this cmdlet belongs to your basic PowerShell repertoire. It will prove invaluable when processing statistical data.
This post will show you several of the different options you have to group statistical data together. And I will illustrate each of these with a sample script.
Continue reading PowerCLI & vSphere statistics – Part 4 – Grouping