add-member

Adding a Percent Free Property to your Get-Datastore cmdlet results using Add-Member

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Update:

 

Thanks to Alan Renouf  (@alanrenouf) for pointing out the New-VIProperty cmdlet to me, I was able to go back to the drawing board and really shorten up my original PowerCLI script by using the New-VIProperty cmdlet. @PowerCLI on twitter also pointed this out shortly afterwards. So after taking a quick look at the reference documentation for the cmdlet, here is my new VIProperty to get the “PercentFree” for each Datastore object returned from the Get-Datastore cmdlet!

 

New-VIProperty -Name PercentFree -ObjectType Datastore -Value {"{0:N2}" -f ($args[0].FreeSpaceMB/$args[0].CapacityMB*100)} -Force

 

To use it, simply run the above in your PowerCLI session, then use “Get-Datastore | Select Name,PercentFree”. A better option would be to load the above New-VIProperty script into your PowerCLI / PowerShell profile. Taking it one step further, @LucD has kindly offered to add this to his VIProperty Module, which means you could instead, just load this module in to your profile and benefit from all the other great VIProperty extensions! Example usage below:

 

New-VIProperty -Name PercentFree -ObjectType Datastore -Value {"{0:N2}" -f ($args[0].FreeSpaceMB/$args[0].CapacityMB*100)} -Force
Get-Datastore | Select Name,FreeSpaceMB,CapacityMB,PercentFree

 

You can find tons of other great VIProperties, or even download the entire module over at LucD’s blog.

 

Original Post:

 

I have been using the Get-Datastore cmdlet quite frequently at my workplace lately – mainly to gather information on various datastores which I export to CSV, then plug into Excel to perform further sorting and calculations on. To save myself a step in Excel each time (creating columns in spreadsheets to show and format the Percent Free figure of each Datastore), I decided to add this into my PowerCLI script.

 

Below, I’ll show you a fairly simple script that will add a member “NoteProperty” (A property with a static value) to your Datastore PS Objects. In the script, we’ll grab all the Datastores based on a search criteria (by default this will get all Datastores or Datastores with the word “Shared” in their name, but you can change it to match what you would like), then we’ll iterate through each, calculate the Percentage of free space from the two figures that we are given back already from Get-Datastore (CapacityMB and FreeSpaceMB), and finally add the member property to the current datastore object. Once this is done, we’ll output the results of  the $datastores object using “Select” to show the Name, Free Space in MB, Capacity in MB, and Percent Free of each object contained within to a CSV file (Remove the | Export-Csv part on the end if you just want the results output to console instead).

 

 

function CalcPercent {
	param(
	[parameter(Mandatory = $true)]
	[int]$InputNum1,
	[parameter(Mandatory = $true)]
	[int]$InputNum2)
	$InputNum1 / $InputNum2*100
}

$datastores = Get-Datastore | Sort Name
ForEach ($ds in $datastores)
{
	if (($ds.Name -match "Shared") -or ($ds.Name -match ""))
	{
		$PercentFree = CalcPercent $ds.FreeSpaceMB $ds.CapacityMB
		$PercentFree = "{0:N2}" -f $PercentFree
		$ds | Add-Member -type NoteProperty -name PercentFree -value $PercentFree
	}
}
$datastores | Select Name,FreeSpaceMB,CapacityMB,PercentFree | Export-Csv c:\testcsv.csv

 

Here’s an example of our output:

 

Note that you could simplify the script by removing the function called “CalcPercent” and adding it to your PowerShell or PowerCLI environment profile. Hope this helps!