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Quick Tip - Locating SRM Placeholder VMs using the vSphere API

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I had received a question the other day from a reader where they were trying to distinguish between the running VM and its placeholder VM due to their use of VMware Site Recovery Manager (SRM). Since the VM name is exactly the same in both vCenter Servers, it was not clear how to identify between the two. As mentioned in my reply to the reader, there are a couple of ways. You could use the SRM API in-conjunction with the vSphere API (in his case, he was using PowerCLI) to be able to check whether the VM in question was the placeholder VM or not.

Another option is to simply use the vSphere API and querying for the managedBy property which is populated when SRM and/or other solutions are associated with managing a set of VMs. In the case of SRM, you will see an extensionKey with value of "com.vmware.vcDR" and type with value of "placeholderVm" which tells you that the VM is an SRM Placeholder VM, pretty easy, right!? 🙂

Since I did not have an SRM environment handy, the next best thing was to check out VMware Hands-On-Lab environment which anyone can access for free. Lab HOL-1705-SDC-1 was exactly what I needed and here is a quick screenshot of the vSphere MOB showing you what the managedBy property looks like in the vSphere API.

To demonstrate the use of this vSphere API, I wrote a quick PowerCLI function called PlaceholderVMs.ps1 and below is an example of running the Get-PlaceholderVM command:

vSphere Content Library versioning 

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A question came up the other day on how versioning is handled when using the vSphere Content Library feature and specifically when you update an existing VM template that already exists in the Content Library (CL, which I will be using throughout the article). Having used CL since vSphere 6.0 which I have also written about it extensively here, I knew that it had a built-in versioning mechanism which would automatically increment as new updates were applied to the VM Templates stored in CL.

One thing that I do not think many folks are aware of is that you can actually retrieve the CL Item Version within the vSphere Web Client. You can do by just adding the "Content Version" column by right clicking on column headers and select show/hide columns to add or remove specific fields.


I figured, this was pretty straight forward and shared my findings with the individual and thought that was it. While working on my Content Library PowerCLI community module, I came to learn there was more than one version that was being returned by the CL API.

Here is an example screenshot showing the three different versions using the Get-ContentLibraryItems (not to be confused with the OOTB Get-ContentLibraryItem cmdlet):


Taking a look at the API documentation, it was still not 100% clear on what all these versions provided and also when would they increment? I reached out to one of the CL Engineers, Eric who then provided me more information on how each of these versions are being used. Lets go through each one of them and I will include an example which also helped me understand how these different "versions" actually work.

Content Version - This particular version will increment as changes are made to the actual file content itself. This is also the same version that is available in the vSphere Web Client UI as shown earlier.

Lets now go through an example workflow to show when this version will get incremented:

  1. Create a new VM called Foo (ContentVersion=N/A)
  2. Clone VM Foo into CL called Foo VM Template (ContentVersion=1)
  3. Clone completes for Foo VM Template (ContentVersion=2) <--The reason this is 2 and not 1 is that when the initial CL Item is created (think of it as a placeholder), the Content Version is incremented
  4. Deploy Foo VM Template to new VM called Bar (ContentVersion=2, no changes on deploy)
  5. Update VM Bar with some changes and clone Bar back to Foo VM Template (ContentVersion=3) <--Changes were made and we now increment the Content Version

Metadata Version - This particular version will only increment for changes made to either the name or description of the CL template.

Version - This particular version is used for concurrency control and this will always increment along with the Metadata Version for local libraries.

Lets now go through an example workflow for a local library to show how these two versions get incremented:

  1. Create a new VM called Foo (MetadataVersion=N/A)
  2. Clone VM Foo into CL called Foo VM Template (MetadataVersion=1, Version=1)
  3. Update the description of Foo VM Template (MetadataVersion=2, Version=2)
  4. Deploy Foo VM Template to new VM called Bar (MetadataVersion=2, Version=2, no changes on deploy)
  5. Update VM Bar with some changes and clone Bar back to Foo VM Template (MetadataVersion=3, Version=3)

Lets now go through an example workflow for a subscribed library to show how these two versions get incremented:

  • Create a new VM called Foo on a local library named CL1 (MetadataVersion=N/A)
  • Clone VM Foo into CL called Foo VM Template (MetadataVersion=1, Version=1)
  • Update the description of Foo VM Template (MetadataVersion=2, Version=2)
  • Create a new subscribed library to CL1 which will download Foo VM Template (MetadataVersion=2, Version=1) <--MetadataVersion must match the publisher, but version does not have to match

After going through a few of these exercises with a few dummy VMs and using my Get-ContentLibaryItems function, I was able to get a better grasp on CL versioning. Hopefully this helpful for anyone who might want to use the CL APIs to track changes between their VM templates and/or files or just being able to see this within the vSphere Web Client UI.

VMware Fusion 2017 Tech Preview adds REST API support

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In case you have not heard the news, the VMware Fusion and Workstation team just released their 2017 Tech Preview releases which you can read more about it here and here. A couple of years back, VMware had released a slimmed down desktop Hypervisor based on VMware Fusion called AppCatalyst which was optimized for developers wanting to run Docker Containers. Although the feedback for AppCatalyst was positive, the large majority of customers preferred to see the AppCatalyst specific features such as the RESTful API to just be included natively within Fusion rather than having a separate product.

Although it could not be said at the time, the feedback was heard loud and clear and the plan was to pull in the AppCatalyst REST API directly into Fusion. With the Fusion 2017 Tech Preview, you will now be able to interact with your Virtual Machines running on Fusion using the new Fusion REST API which also includes some additional new capabilities that was not there with the AppCatalyst REST APIs such as network and port forwarding management.

UPDATE (09/27/17) - VMware Fusion 10 has just officially GA'ed and there have been number of updates and enhancements since the Tech Preview. From an Automation/API standpoint, there have been several major updates that I would like to call out.

First, there are several new command-linen options to the vmrest utility including support for both HTTP and HTTPS API endpoints, credentials are also now supported so you can setup a shared username/password and ensure that only authorized folks can login to the API and lastly, the default port is now also configurable. Along with these widely requested features during the Tech Preview, there is also a nice debugging option while using the Fusion UI for troubleshooting purposes.

Secondly, the Fusion Swagger REST API docs has received a total re-vamp in terms of organization and cleaned up documentation. Below is a screenshot of the Swagger interface for the GA version of Fusion 10 which should make it even easier to consume the REST API.

Getting Started

Step 1 - Once you have installed the Fusion 2017 TP release, you will need to start the REST API endpoint which is provided by /Applications/VMware Fusion Tech Preview.app/Contents/Public/vmrest You can just type vmrest and it should automatically start or if you prefer to run it in the background, just type the following:

vmrest &

Here is screenshot of starting the Fusion REST API endpoint:


Note: The default port for the REST API is 8697

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