How to prepare for VMware vSphere upgrade?

By | January 20, 2016

When it comes to upgrading the vSphere environment, we have to (or at least should ๐Ÿ˜‰ ) prepare for it carefully. I have done many vSphere projects and in order for upgrades to be successful, it's necessary to do some pre-ugrade tasks ๐Ÿ™‚ In this article we discuss the following topics:

  • Why to perform an upgrade?
  • What is the correct vSphere upgrade/update sequence?
  • What should we check before the upgrade of vSphere?

Performing vSphere upgrade - main reasons

In my opinion, upgrades arenโ€™t necessarily a good or bad idea in general, but you should upgrade only if you can point to three main reasons as follows:

  • End of support for products
  • Security
  • New features

You shouldnโ€™t upgrade because you feel as though you โ€œhave toโ€ implement new technology. Instead, there should be a clear benefit for doing so, and one that outweighs the costs. Yes, yes, costs are very important... ๐Ÿ˜‰

End of support

As every software, vSphere has a lifecycle, which begins when a specific version is first introduced to us and ends when VMware no longer provides support for that product. As a quick reminder, VMware provides the following product lifecycle phases:How to prepare for VMware vSphere upgrade - lifecycle product

  • General availability - The General Support phase begins on the date of general availability of a Major Release (โ€œGAโ€) and lasts for a fixed duration.
  • End of general support - A product has reached its end of support life when it is no longer generally supported by VMware.
  • End of technical guidance - if available, is provided from the end of the General Support phase and lasts for a fixed duration.

New Features

Features - our new toys and reasons to not sleep all the night ๐Ÿ˜‰ Usually, a new version of vSphere or other VMware product changes existing features and adds new ones, but sometimes the changes mean that old features aren't available any more or are not supported. Some months ago vSphere 6.0 was released with some very cool features such as Virtual Volumes (VVOLs) or Long Distance or Cross vCenter vMotion. I have had recently a project where my customer wanted to achieve Recovery Time Objective (RTO) and Recovery Point Objective (RPO)ย  - 0 for VM with 4vCPU. As you can guess Multi-CPU Fault Tolerance available in vSphere 6 can meet requirements however the upgrade of vSphere needs to be done.

Security and bugs

The next reasons are security and bugs. Upgrade should address/correct bugs encountered in prior version, however, in practice, an update should be enough. Sometimes we have to upgrade because some issues do not have workarounds but the same issues are not available in a higher version ๐Ÿ™‚

Pre-upgrade tasks

You should make friends with VMware Compatibility Guide and VMware Product Interoperability Matrix ๐Ÿ™‚ You can find there all important information such as storage arrays support with specific firmware or type of server. There are some really fundamental pre-upgrade tasks:

  • Checking hardware and software compatibility
  • Checking general interoperability
  • Checking solution/database interoperability
  • Checking upgrade path and sequence

Checking compatibility

Let's assume that you want to upgrade your infrastructure to vSphere 6.0. You have some HP DL380p servers and you would like to check whether there are supported by vSphere 6.0. You need to go to the VMware Compatibility Guide and choose "Systems/Servers" section as shown on the below figure. Then you need to choose product release version, partner name or keyword etc:How to prepare for VMware vSphere upgrade - checking compatibility

Ufff, your servers are supported by vSphere 6.0 ๐Ÿ˜‰

Because you use Site Recovery Manager for DR purpose, you would like to check what Storage Replication Adapters (SRA) are supported by SRM. You need to choose "Site Recovery Manager" section as shown on the below figure:How to prepare for VMware vSphere upgrade - checking compatibility2


If you click on specific version of SRA, you can check what firmware versions of storage arrays are supported:How to prepare for VMware vSphere upgrade - checking compatibility3


Checking general Interoperability

Sometimes it is necessary to keep mixed version of ESXi hosts in vCenter inventory (for example, your HP DL380p servers are not supported by a newer vSphere version). To confirm it, you should open the VMware Product Interoperability Matrix and:

  1. Select a Solution
  2. Add Platform/Solution and optionally select "Do not show empty rows"

How to prepare for VMware vSphere upgrade - Interoperability

As shown on the above figure, vCenter Server 6.0 supports ESXi hosts 6.0 and 5.x as well.

Checking Solution/Database Interoperability

Some VMware products use databases. It is necessary to check if databases are compatible. For example, you would like to continue using vCenter Server installed on Windows (even my vCenter on Windows vs vCenter Appliance (VCSA) post ๐Ÿ˜‰ ) and database located on Microsoft SQL 2014. You can open the Solution/Database Interoperability and confirm the compatibility:

  1. Select a VMware Product and Version - VMware vCenter Server 6.0
  2. Add Database - select Mictosoft SQL Server 2014 Enterprise - 64-bit

How to prepare for VMware vSphere upgrade - Solution Database Interoperability

Checking Upgrade Path

When you do an upgrade, you would like to do it directly (e.g. from 5.1 to 6.0 but no 4.1 to 5.5 and then 6.0). You can check the upgrade path in VMware Product Interoperability Matrix as well.

How to prepare for VMware vSphere upgrade - path

vSphere upgrade/update sequence

Ok, you have checked compatibility all your products and hardware. Which product should be upgraded first? Fortunately there are some VMware KB with correct upgrade/update sequence:

So based on upgrade sequence for vSphere 6.0 and compatible VMware products, let's assume that you have the following products in your environment:

  • Backup solution (NetBackup)
  • vCenter Server
  • vCenter Site Recovery Manager
  • ESXi hosts
  • vSphere Replication

The supported upgrade/update should be as below

  1. If Applicable/necessary, update/upgrade the NetBackup environment.
  2. If Applicable, upgrade the External vCenter Single Sign-On instance
  3. Upgrade vCenter Server
  4. Upgrade vSphere Replication
  5. Upgrade vCenter Site Recovery Manager
  6. Upgrade ESXi

So as shown above, you should consider not only VMware but also other thirdy party softwares such as:

  • Backup/recovery solutions
  • Automation tools
  • Monitoring tools
  • Workflows /orchestators

For example, if you do not confirm that a backup solution you use supports a version of vSphere/vCenter you want to upgrade to... you could not able to backup your VMs (or at least it could not be supported by backup vendor). The VMware policy concerning backward and forward compatibility is for VDDK to support N-2 and N+1 releases, however your backups solution may not support a correct version of VDDK.


I have shown some fundamental steps that you should do before the upgrade of vSphere products. The upgrade needs to have a project plan as well.

Author: Mariusz

Architect (~ 15 years experience based on passion...) with strong background as a System Administrator and Engineer. Focused on Data Center Solutions: Virtualization/Cloud Computing and Storage/Backup Systems. Currently living in Poland.