How to validate VMware Certifications

It seems of late there is more and more people claiming to be VCDX as well as VCAP when they are not. This to me shows the people have no integrity and I would not want to work with a person who lied about a certification to try and get a job.

Luckily there is an easy way to validate if a person has a certification or not.

For VCDX its super easy, visit and enter the persons First Name, Last Name , VCDX Number or Company and you can quickly find out if they are VCDX or not.

See example below:


Another way is to have the person login to and open their transcript. The transcript shows all VMware certifications including VCA , VCP, VCAP , VCIX and VCDX.

The following shows part of my transcript which shows VCDX, VCAP and VCP certs inc:

  • VMware Certified Design Expert – Cloud
  • VMware Certified Advanced Professional – Cloud Infrastructure Administration
  • VMware Certified Professional – Cloud


You will also see the “Share” button, what this does is allow you to give a URL to a prospective employer or recruiter for them to validate your certification/s.

To use this facility, simply click the “Share” button and you will be prompted with a window similar to the below:


This gives you two options:

1. Share the PDF version of your certificate with anyone by simply copy and pasting the URL.

You will see something similar to this:


2. Share the Certification Authentication form URL and Code and allow anyone to check the current status of your certification.

The following is what you will see when you click the Authentication Form button:


Simply type the random numbers and click Authenticate and you will see something similar to the below:CertFound

Simple as that!

I hope this post helps potential employers and recruiters validate candidates credentials and stamp out this growing trend of people claiming they have VMware certifications (especially VCDX) when they don’t.

NOS & Hypervisor Upgrade Resiliency in PRISM

I have had several prospective and existing customers say how much they like the One Click upgrade PRISM provides for NOS, Hypervisor’s, Firmware and NCC. These customers typically also ask questions about what happens if they perform a One Click upgrade and the cluster is for any reason degraded such as from a drive, node, block failure.

Before starting a One Click upgrade, NOS always performs Pre-Upgrade checks to ensure the cluster is healthy. In the event the cluster is not fully resilient the upgrade process will be aborted as shown below:



In the above case, the cause of the cluster being “under-replicated” (meaning the configured Resiliency Factor of 2 or 3 was not in compliance) was due to the fact NOS had just be upgraded on the cluster and one of the nodes had not yet come back online when the One Click Upgrade for the Acropolis hypervisor (AHV) was started.

Other situations where the cluster may be under replication is following a HDD, SSD, Node or Block failure. In all these cases, the Nutanix Distributed File System (NDFS) will restore resiliency assuming sufficient rebuilt capacity is available in the Storage Pool. This is why Nutanix always recommends clusters be designed with at least N+1 available capacity to ensure rebuild capacity exists and the cluster can automatically self heal.

As a general rule it is recommended to wait for approx 10 mins between NOS and Hypervisor upgrades to avoid these kind of issues, or you can simply check the Home screen of PRISM and ensure the Heath status is Good as shown below:


and that the Data Resiliency Status is “OK” as shown below.DataResiliencyOk

Both the Health and Data Resiliency status are Hypervisor agnostic and appear on the Home screen of all Nutanix deployments.

If both the Health Status and Data Resiliency are good then you can go ahead and start the upgrade and it should complete successfully.


PRISM will not start an upgrade of NOS or the Hypervisor if the cluster is degraded, so you can rest assured that even if you attempt an upgrade by accident when the cluster is degraded, NOS will protect you.

Related Posts:

1. Scaling Hyper-converged solutions – Compute only.

2. Acropolis Hypervisor (AHV) I/O Failover & Load Balancing

3. Advanced Storage Performance Monitoring with Nutanix

4. Nutanix – Improving Resiliency of Large Clusters with Erasure Coding (EC-X)

5. Nutanix – Erasure Coding (EC-X) Deep Dive

6. Acropolis: VM High Availability (HA)

7. Acropolis: Scalability

Acropolis Hypervisor (AHV) I/O Failover & Load Balancing

Many customers and partners have expressed interest in Acropolis since it was officially launched at .NEXT in June earlier this year, and since then lots of questions have been asked around resiliency/availability etc.

In this post I will cover how I/O failover occurs and how AHV load balances in the event of I/O failover to ensure optimal performance.

Let’s start with an Acropolis node under normal circumstances. The iSCSI initiator for QEMU connects to the iSCSI redirector which directs all I/O to the local stargate instance which runs within the Nutanix Controller VM (CVM) as shown below.


I/O will always be serviced by the local stargate unless a CVM upgrade, shutdown or failure occurs. In the event one of the above occurs QEMU will loose connection to the local stargate as shown below.AHVMPfailedlocal

When this loss of connectivity to stargare occurs, QEMU reconnects to the iSCSI redirector and establishes a connection to a remote stargate as shown below.AHVMPremote

The process of re-establishing an iSCSI connection is near instant and you will likely not even notice this has occurred.

Once the local stargate is back online (and stable for 300 seconds) I/O will be redirected back locally to ensure optimal performance.


In the unlikely event that the remote stargate goes down before the local stargate is back online then the iSCSI redirector will redirect traffic to another remote stargate.

Next lets talk about Load Balancing.

Unlike traditional 3-tier infrastructure (i.e.: SAN/NAS) Nutanix solutions do not require multi-pathing as all I/O is serviced by the local controller. As a result, there is no multi-pathing policy to choose which removes another layer of complexity and potential point of failure.

However in the event of the local CVM being unavailable for any reason we need to service I/O for all the VMs on the node in the most efficient manner. Acropolis does this by redirecting I/O on a per vDisk level to a random remote stargate instance as shown below.


Acropolis can do this because every vdisk is presented via iSCSI and is its own target/LUN which means it has its own TCP connection. What this means is a business critical application such as MS SQL / Exchange or Oracle with multiple vDisks will be serviced by multiple controllers concurrently.

As a result all VM I/O is load balanced across the entire Acropolis cluster which ensures no single CVM becomes a bottleneck and VMs enjoy excellent performance even in a failure or maintenance scenario.

As i’m sure you can now see, Acropolis provides excellent resiliency and performance even during maintenance or failure scenarios.

Related Posts:

1. Scaling Hyper-converged solutions – Compute only.

2. Advanced Storage Performance Monitoring with Nutanix

3. Nutanix – Improving Resiliency of Large Clusters with Erasure Coding (EC-X)

4. Nutanix – Erasure Coding (EC-X) Deep Dive

5. Acropolis: VM High Availability (HA)

6. Acropolis: Scalability

7. NOS & Hypervisor Upgrade Resiliency in PRISM