This post will address some basic questions and give you clear answers on important phases of VMware vSphere upgrade.

One of the first tasks when it comes to upgrading a virtual infrastructure running VMware vSphere is probably version verification. You must know exactly which versions of vCenter Server are installed and which versions of ESXi hosts are installed in the entire environment.

This is because you cannot simply upgrade from any version to any version. To put it simply, there's no possibility to upgrade from some versions to 6.7, but you can upgrade them to 6.7 U1.

Note: At the time of this post, the latest version of vSphere is 6.7 U1.

You can verify this at a VMware website called VMware Product Interoperability Matrices.

VMware Product Interoperability Matrices

VMware Product Interoperability Matrices

The website image is interactive, so if you place the cursor over one of the red marks, you'll get a nice explanation about what's supported and what isn't.

Some versions do not have a direct upgrade path

Some versions do not have a direct upgrade path

In this case, you have to upgrade vSphere 5.5 first to 6.0 or 6.5 and only then to 6.7 or 6.7 U1.

Why can't I upgrade to the latest version? ^

The second reason you may not be able to upgrade to the latest version of VMware vSphere is because your backup vendor may not support the latest version of vSphere.

This happens every time VMware releases an upgrade or a major release. It can take up to six months for some vendors to support the latest version.

So check with your backup vendor to find out whether your backup product is compatible or not before you start upgrading your virtual infrastructure.

How can I back up vCenter before the upgrade? ^

Since you need to upgrade vCenter Server first, you'll need to create a backup of your vCenter Server. Here you can have several scenarios:

  1. vCenter Server on a Windows virtual machine (VM): take a backup of the whole VM with your backup software.
  2. vCenter Server on Windows (physical): take an image-level backup (with Acronis, Veeam Agent for Windows, or another software product that can do image-level backups).
  3. vCenter Server Appliance (VCSA) – Linux-based vCenter Server: Again, take a backup with your backup software. You never know what might go wrong.

If you are running vSphere 5.5, I think you already know the end of general support (EoGS) for vSphere 5.5 occurred on September 19, 2018.

What about other VMware products? ^

This is possible, and you should make sure to check the VMware Product Interoperability Matrices where you'll need to select the Interoperability tab and enter the product versions you're currently running.

VMware Interoperability example vSphere 6.0 and Horizon 7.0

VMware Interoperability example vSphere 6.0 and Horizon 7.0

Note that before starting the upgrade of vCenter Server, VMware recommends noting any other VMware solutions associated with your environment, such as Site Recovery Manager (SRM) or VMware NSX.

VMware supports upgrades to vCenter Server 6.7 from vCenter Server 6.0 and above. A migration tool is also available to convert your deployment from vCenter Server for Windows to the VCSA.

Supported scenarios include:

  • vSphere 6.0 to 6.7U1
  • vSphere 6.5 to 6.7U1
  • vSphere 6.5U2 to 6.7U1

However, vSphere 5.5 to 6.7U1 is not supported. Note also that 6.5U2 to 6.7 is still unsupported, and you must upgrade only to 6.7U1 if you're on 6.5U2.

ESXi upgrades ^

Once you have upgraded the different VMware products and vCenter Server, it's time to upgrade your ESXi hosts. Here you might start with your management cluster first (if your architecture has one).

You can use VMware Update Manager (VUM), which is now built into the VCSA and is an integral part of the product. Previously the VUM was a separate component, and this is especially true for vCenter Server installations on Windows systems.

Working with VUM is VMware's recommended way when it comes to ESXi upgrades. There are several ways to upgrade the cluster, and you can also specify an automatic upgrade of the cluster that will automatically evacuate VMs to the remaining hosts.

If you prefer to pay more attention to the upgrade process, just apply the update, evacuate one host at a time, and put it into maintenance mode.

Then select Remediate, accept the license, and check the settings to see if everything looks good.

To evacuate the VMs from the hosts automatically, you have to put a Distributed Resource Scheduler (DRS) into automatic mode.

VMware vSphere DRS fully automated

VMware vSphere DRS fully automated

Once you have upgraded all of your hosts and you think that you might be finished, it isn't really true.

You'll still have to check all VMs and see whether they need a VMware Tools upgrade. After a major infrastructure upgrade, VMware recommends always checking whether VMware Tools needs an upgrade and whether they are running their latest release.

VMware Tools upgrade

VMware Tools upgrade

Virtual hardware version upgrade ^

A VM's hardware version reflects the VM's supported virtual hardware features. These features correspond to the physical hardware available on the ESXi host on which you create the VM.

For example, if you upgrade VM hardware version 10 (introduced in vSphere 5.5) to VM hardware version 14 (introduced in vSphere 6.7), your VM will suddenly have the possibility to run a Virtual Trusted Platform (vTPM) 2.0 module.

VMware recommends that you upgrade VM hardware only if you really need features present in the new virtual hardware version. Otherwise, it's like changing a motherboard for a server. And there is no simple way back.

Final words ^

Before every upgrade of any infrastructure, you should gather all necessary knowledge, all documentation sets for upgrades, and study it. Only after that, you should check the overall vSphere architecture you need to upgrade.

Lastly, you should also check whether vCenter Server and Platform Services Controller (PSC) are separate or running on the same system. Depending on which, the upgrade path and upgrade steps may vary.

Subscribe to 4sysops newsletter!

This post delivers only a fraction on what's necessary for an upgrade and does not even go into enough details. However, hopefully it teaches you few tricks that will help you successfully upgrade your virtual environment. Believe me, every year, it becomes easier and easier.

1 Comment
  1. Paolo Maffezzoli 3 years ago

    Thank you for your interesting article. I agree with your approach, in my experience the first big activity is find what is supported and what is not. In general when you start with the upgrade process a Backup is a must, backup, backup and backup….

Leave a reply

Your email address will not be published.


© 4sysops 2006 - 2022


Please ask IT administration questions in the forums. Any other messages are welcome.


Log in with your credentials


Forgot your details?

Create Account