Addressing errors when using vRA 7.4 Guest Agent

Having upgraded my vRA instance in my HomeLab to 7.4 not long after it GA’d, I recently decided to create some nice, new templates as well. You know, latest patches, hardware, basic config etc.

I won’t bore you with exactly how I installed Windows, patched it or configured it. The relevant part of the process to this article was the installation of the vRA Guest Agent and subsequent testing of it.

I already had my vRA blueprint configured; just a simple Windows Server 2012 R2 template that has the vRealize LogInsight agent installed and configured on it automatically as part of the provision process:

Installing the vRA Guest Agent

This is a documented process to install the software agent on a Virtual Machine that is then subsequently turned in to a template. For vRA 7.4, the documentation can be found on VMware’s site:

Install the Guest Agent on a Windows Reference Machine

Prepare a Windows Reference Machine to Support Software

This worked without issue. I shutdown the machine, turned it in to a template and update my blueprint.

Testing the new template

This is where I ran in to an issue. Continue Reading


Automating vSphere VM disk zeroing with vRA7 and vRO

A long time ago, on a project far back in time, the team that I was part of was given a requirement to zero the disks of VMs before they were deleted by vRA / vRO (or vCAC and vCO as they were called back then). One of my colleagues on the project, Jonathan Medd, devised an approach for doing this using an “experimental” PowerCLI feature and wrote it up on his blog.

Fast forward nearly two and a half years and I’m looking at an upgrade for this platform and wondering if there’s a way to accomplish the same task in vRO rather than by breaking out to PowerCLI. Don’t get me wrong, I love PowerCLI. But fewer parts would mean that there’s less to go wrong. How to do it then…

Disk zeroing in PowerCLI

This is still listed as an experimental feature in the PowerCLI documentation for vSphere 6.5. The Set-HardDisk cmdlet has the -ZeroOut option and it would still be used exactly as Jonathan describes it in his article.

PowerCLI documentation for Set-HardDisk

PowerCLI documentation for Set-HardDisk

Disk zeroing in vRO

I’m not sure when it was added (i.e. which version), but back in 2014 we couldn’t find equivalent functionality in vRO. I did a quick search of the vCenter plugin methods in my v7.2 appliance and couldn’t see it there either. It turns out though that I was having a bad typing day. Burke Azbill pointed me to the right place (thank you):

vRO API help for zeroFillVirtualDisk_Task

vRO API help for zeroFillVirtualDisk_Task

So, “zeroFillVirtualDisk_Task” is a method called from VcVirtualDiskManager. All we need to give it is a datastore path and a VcDataCenter object and it’ll do the rest.

Getting a datastore path is relatively straight forward. Using vSphere’s Managed Object Browser (MOB), I can pick a VM object and navigate down to the config (1) and the hardware (2), get the disk devices (3) and look at their backing (4). The fileName attribute gives me the datastore path that I need.

Example VM configuration information in the vSphere MOB

Example VM configuration information in the vSphere MOB

Obtaining a VcDataCenter object, if I have the VM object already is a doddle too. There’s a vCenter plugin action that will do it for me based on the information that I have available to me in the MOB above. Taking the datastore attribute, which is a reference to a datastore object, I can pass it to the action below and get the VcDataCenter back.

Library vRO action getDatacenterForDatastore

Library vRO action getDatacenterForDatastore

Putting it together

Starting with a vCenter VM (vm in the script below) object in vRO then, zeroing all of the VM’s disks can be achieved as follows:

Deconstructing the code:

Line 1 – Gets the vCenter plugin connection for the vCenter that owns the VM called vm.
Line 2 – Gets the VCVirtualDiskManager object that the zeroFillVirtualDisk_Task method is a member of.
Lines 3 to 5 – Getting the config, hardware and devices for the VM. This could be done as one line.
Line 9 – Starts a loop to run the following code for each device.
Line 10 – Checks to see if the current device is a Virtual Disk.
Line 11 – Gets the Virtual Disk filename.
Line 12 – Gets the VcDataCenter object using the Virtual Disk datastore as an input.
Line 14 – Instructs vCenter to zero the Virtual Disk.

Considerations for vRA

There are a few considerations aside from some minor tweaks to make the code more efficient or robust before we look at adding this as a workflow subscription in vRA.

  • Firstly, on some storage devices (my home lab included), zeroing the disks causes a thin provisioned disk to expand to its full size. If the disks are large, you can expect the task to take some time and / or consume a lot of storage space.
  • Secondly, if there are snapshots running on the VM, they must be removed first.
  • Thirdly, the VM must be powered off before this will run. If the workflow subscription takes place at the right time, this shouldn’t be a problem however.
  • Finally, as I’ve already mentioned, this process could take some time to complete. The zeroFillVirtualDisk_Task method returns a vCenter task reference. Ideally that should be monitored for completion rather than just firing and forgetting. If the VM has multiple disks, that’s multiple tasks.

Adding it to the vRA Event Broker

Taking the original script above and factoring in the considerations too, it’s possible to create a fairly simple workflow that can be added as an Event Broker subscription in vRA. I’ll post it up here soon.


How to change the vRA 7.2 “All Services” icon using vRO

This post was inspired by Ryan Kelly’s recent post of a similar title in which he revealed how to change the “All Services” icon in the vRA 7.2 Catalog tab. Shortly after seeing that, I noticed that Ricky El-Qasem had also posted on the subject and created a small utility to accomplish the same task.

Great posts both of them. But I wanted to take a slightly different route and accomplish the same task in vRO which, as I’m sure you know, comes bundled with vRA. I must admit that I’m not totally satisfied with the result, maybe about 95%, but I’ll explain why later.

Selecting a source image

For my initial testing, I thought I’d use the image on Ryan’s post as it clearly worked for him. However, the image in his post is JPEG formatted and contains a border. That would clearly look a bit naff so I converted it to a PNG file, removed the border and the white background.

For guidance, I’d recommend a PNG file for these icons so that if they’re not square the image background can set to be transparent, allowing the theme from vRA to show through. It just looks better.

The process

As vRO allows images to be imported and stored within it, I thought I would try this approach. I have previously used such Resource Elements to attach images to HTML emails sent by vRO (as well as to store templates for text / emails, JSON objects and XML).


From that point, it should simply have been a case of converting the image to Base64 text within vRO and executing a REST update to vRA to replace the image. However, the methods available for extracting data from a Resource Element convert the image to a string, which munges it a bit. The resulting Base64 string is therefore corrupt and you end up with a broken image displaying in vRA:


I tried various ways to get around the issue but so far I haven’t been able to, hence my minor dissatisfaction. What this means is that like the method that Ryan outlined, you still have to convert the image to Base64 outside of vRO. To finish off the workflow that I wanted to create, I did just that using an online tool and stored the Base64 string in a different resource element in vRO.

In the RAW output for the image shown, only the actual Base64 text is required and can be placed in to a text file and added to vRO:


This changed the process in the workflow slightly. In some ways it simplified it. Let’s look at that now…

Looks fairly simple, doesn’t it? Actually it is. No messing around with tokens!

Line 2 – This returns the vCACCAFE:VCACHost connection for the default tenant in vRA (vsphere.local)
Line 4 – Creates a REST connection to the vRA Catalog Icon Service
Lines 7 & 8 – Creates a reference to the default tenant organisation in vRA
Lines 11 to 16 – Constructs a new icon object using the Base64 image data as well as the ID of the image we’re replacing
Line 19 – Execute!

The result

In the workflow, I’ve added three inputs:

  1. Select a resource element where the base64 image data is stored (using this overrides the field below).
  2. Paste in the base64 image data yourself.
  3. Set the MIME type of the image (i.e. PNG or JPG)

Running it against Ryan’s icon and the Union flag image from above, I got the change applied across all tenants in vRA as expected:

Want the workflow to try this yourself? I’ve popped it on to GitHub:



vRealize Automation Extensibility Migration Guide

20170241_190240-CapturFilesPossibly a little overdue, but valuable all the same, the vRealize Automation Extensibility Migration Guide was published earlier this week and is a must-read for anyone looking at upgrading or migrating their vRA 6.x installation to vRA 7.x.

The document explains the differences between the extensibility features of the two versions above and how existing customised functionality can be adapted to best work with vRA7.

The guide is very detailed but clearly can’t cater for every customer use case (that would be a very big document).