Deans Blog

I was recently looking into tackling VM sprawl (with no budget!) one thing I wanted to discover was when the virtual machine was created to allow for the  discovery of the count created in a certain time period, and while I was at it who created the VM.

I then found an excellent script compiled by Alan Renouf (@alanrenouf) at http://www.virtu-al.net/2010/02/23/who-created-that-vm. The script has a dependancy on vSphere PowerCLI (obviously!) and ActiveRoles Management Shell for Active Directory and creates two custom virtual machine custom fields named ‘CreatedBy’ and ‘CreatedOn’ and retrieves the values for $Event.Username and $Event.CreatedTime attributes using the Get-VIEvent cmdlet and filtering the discover to the following types;

VmBeingDeployedEvent
VmCreatedEvent
VmRegisteredEvent
VmClonedEvent

On the initial run of the above script using the WhatIfPreference I noticed that the $Event.CreatedTime would be output the date string in the following format ‘MM/DD/YYYY HH:MM:SS’ when used in a variable. Interesting enough the $Event.CreatedTime value was in the following format ‘DD/MM/YYYY HH:MM:SS’.

So how was this occurring? My conclusion was that it was due to the default culture format used in Powershell by our cousins over the pond ‘en-US’, to provide evidence to the case I added a couple of lines to the script provided to convert the date format using the CultureInfo Class as below and this resolved my issue, providing the date the VM was created in the correct format.

$Culture = New-Object System.Globalization.CultureInfo(“en-GB”)
$Created= $Date.ToString(“G”, $Culture)

So that now gives me the building blocks to see how many and when the virtual machines were created and by whom. Obviously for those in the US the script is good to go, however those of us in the UK will need to initialise the en-GB culture setting to convert the date to the correct format.

Therefore the only modification I made to the script was the final script block to include the below:

$Culture = New-Object System.Globalization.CultureInfo(“en-GB”)
$Created = $Date.ToString(“G”, $Culture)
Write “Adding info to $($VM.Name)”
Write-Host -ForegroundColor Yellow “CreatedBy $User”
$VM | Set-CustomField -Name “CreatedBy” -Value $User | Out-Null
Write-Host -ForegroundColor Yellow “CreatedOn $Date”
$VM | Set-CustomField -Name “CreatedOn” -Value $Date | Out-Null
}

Information on the CultureInfo  Class can be found here http://msdn.microsoft.com/en-us/library/system.globalization.cultureinfo.aspx and the specifiers for the string format here http://technet.microsoft.com/en-us/library/ee692801.