Creating an EagerZeroedThick disk with PowerCLI

Hey… -  that is not possible – I hear you say – well in principle you are right. Up until today…

By mistake of course – I found that there was a change made to the 5.1 release of PowerCLI – but this change has not been documented anywhere – which I think is a shame. This post is the only public reference I know of.

Up until the 5.1 release you could not create an EagerZeroedThick hard disk with PowerCLI. Let’s look at the 5.0 documentation for PowerCLI.

New-Harddisk

As you can see above the options are Thin or Thick and if you go to look at the
VirtualDiskStorageFormat – Enum you will see the that there is no EagerZeroedThick option.

Enum

The PowerCLI changelog has a new Cmdlet Move-Harddisk – which as you can see allows you to migrate a VMDK from one location to another – and if you also noticed..

5.1 New-Harddisk

Yep, EagerZeroedThick is one of the options as you can see above. The VirtualDiskStorageFormat – Enum was not updated though.

So I used this today as part of a bigger automation process to prepare some VM’s for Oracle RAC (which I will post about in the not too distant future)

get-vm $vm1 | New-HardDisk -DiskType flat -CapacityGB 2 -StorageFormat EagerZeroedThick -Datastore $dbds |New-ScsiController -Type ParaVirtual -BusSharingMode NoSharing

Which is so much easier than… (taken from Luc Deken’s post)

$vmName = <vm-name>
$vCenter = <vCenter-name>
$esxAccount = <ESX-account>
$esxPasswd = <ESX-password>

function Set-EagerZeroThick{
	param($vcName, $vmName, $hdName)

# Find ESX host for VM
	$vcHost = Connect-VIServer -Server $vcName -Credential (Get-Credential -Credential "vCenter account")
	$vmImpl = Get-VM $vmName
	if($vmImpl.PowerState -ne "PoweredOff"){
		Write-Host "Guest must be powered off to use this script !" -ForegroundColor red
		return $false
	}

	$vm = $vmImpl | Get-View
	$esxName = (Get-View $vm.Runtime.Host).Name
# Find datastore path
	$dev = $vm.Config.Hardware.Device | where {$\_.DeviceInfo.Label -eq $hdName}
	if($dev.Backing.thinProvisioned){
		return $false
	}
	$hdPath = $dev.Backing.FileName

# For Virtual Disk Manager we need to connect to the ESX server
	$esxHost = Connect-VIServer -Server $esxName -User $esxAccount -Password $esxPasswd

# Convert HD
	$vDiskMgr = Get-View -Id (Get-View ServiceInstance -Server $esxHost).Content.VirtualDiskManager
	$dc = Get-Datacenter -Server $esxHost | Get-View
	$taskMoRef = $vDiskMgr.EagerZeroVirtualDisk\_Task($hdPath, $dc.MoRef)
	$task = Get-View $taskMoRef
	while("running","queued" -contains $task.Info.State){
		$task.UpdateViewData("Info")
	}

	Disconnect-VIServer -Server $esxHost -Confirm:$false

# Connect to the vCenter
	Connect-VIServer -Server $vcName -Credential (Get-Credential -Credential "vCenter account")
	if($task.Info.State -eq "success"){
		return $true
	}
	else{
		return $false
	}
}

Set-EagerZeroThick $vCenter $vmName "Hard disk 1"

Ah the little things…

I wonder what other gems are hidden deep in the bowels of PowerCLI that were not updated in the changelog/release notes??… What do you think ??