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

 

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!

 

More PowerCLI basics – Host operations

 

On my quest to learn more about PowerCLI, I have been playing around with some more cmdlets in my lab. As a simple task, I have figured out how to tell ESX or ESXi hosts to enter and exit maintenance mode. Here’s how we do this. First of all ensure you are connected to your vCenter server instance using Connect-VIServer ServerName.

 

Enter maintenance mode:

Set-VMHost ESXi-01.noobs.local -State "Maintenance"

 

Exit maintenance mode:

Set-VMHost ESXi-01.noobs.local -State "Connected"

 

Set host to “disconnected” state:

Set-VMHost ESXi-01.noobs.local -State "Disconnected"

 

So now that we know the basics of setting the state of a VMware host, how about we get slightly more technical and perform one of the above operations on a bunch of hosts in one go? Powershell / PowerCLI is all about automation after all! Note that in the following script, I have also include a simple “if / else” statement to prompt the user running the script manually as we are about to send all ESX(i) hosts into maintenance mode! Use this at your own risk of course, it is just for demonstration purposes. You may want to modify to select hosts to enter maintenance mode on certain criteria. For example, all hosts in a particular cluster, or all hosts with a certain property. Here is the script I would use to perform the operation on all the ESX(i) hosts found in vCenter:

 

$VCServer = “yourvcservername”
Connect-VIServer $VCServer
$confirm = Read-Host “Are you sure you want all hosts to enter maintenance mode? (type yes to continue) “
if ($confirm -eq "yes")
{
	Get-VMHost | Set-VMHost -State "Maintenance"
}
else
{
	"Script aborted (you didn't confirm by typing yes)"
}

 

Once the script is executed, you should get a progress indicator whilst hosts are being dealt with. Afterwards you’ll get some output from each host listing its relevant Connection Status and statistics. Like so:

 

In the above example, we set some variables, and use some basic logic checking with an IF ELSE statement and an equal to (-eq) operator. We also see how to perform a few operations on ESX or ESXi hosts. I hope this helps anyone starting out with PowerCLI. Please do leave any comments, suggestions or improvements in the comments section!

 

Hello PowerCLI

 

So today is the first time I am trying out PowerCLI for vSphere. Yes, I know I am late to the game in the VMware scene, but I hope to start learning more about PowerCLI and start automating some tasks that are currently being done manually where I work.

 

Here is my first try at connecting to my lab vCenter server 🙂

 

Pretty simple really, just as the banner text says, use:
Connect-VIServer servername and
Get-VM

to connect and get a list of VMs. I guess this is my “Hello World” start out with PowerCLI then. If anyone has any tips or quick and easy cmdlets to run in PowerCLI to get information back, please drop a comment with them below. I would also love to know how to iterate through a list of VMs and check whether they have snapshots or not! That would be a great start to what I am looking to achieve.

Cheers!