How to do it...

The following procedure walks you through the steps involved in planning a vSphere upgrade:

1. Hardware capacity and software requirements check: As with any new vSphere version, vSphere 6.5 does come with revised hardware capacity and software requirements. It is important to understand these requirements during the planning phase. VMware provides access to more than one form of reference material that would help you understand the hardware and software requirements to deploy a vSphere environment. One of the primary reference sources is the product documentation and in this case, the vSphere 6.5 Installation and Configuration guide (https://docs.vmware.com/en/VMware-vSphere/6.5/vsphere-esxi-vcenter-server-65-installation-setup-guide.pdf). Another source that is always kept up to date is VMware Knowledge Base (https://kb.vmware.com/s/).
2. Hardware compatibility check: The existing server hardware should be verified for its compatibility with ESXi 6.5. It is done by looking up the current server hardware's make and model in the VMware Compatibility Guide, which can be accessed at https://www.vmware.com/resources/compatibility.

1. vCenter component compatibility checks: The existing Microsoft Windows Servers hosting the vCenter components should be verified for its supportability with vCenter 6.5 and its components.
2. Product interoperability check: vCenter being the core management layer, there are other solutions that connect with vCenter through APIs to provide its services. Therefore, it becomes critical to verify whether the solution vendors, be it VMware or third party, has a vCenter 6.5 compatible solution yet. Also, consider upgrading the solutions and its plugins before you upgrade to vCenter 6.5. For instance, the first release of vSphere 6.5 did not add support for NSX. It was vSphere 6.5.0a that added support for NSX 6.3.
3. Upgrade paths: Depending on the current vSphere version and its deployment model, the process of upgrading to vSphere 6.5 could differ. Hence, it is important to understand the upgrade paths available. The oldest possible version that supports a direct upgrade is vSphere 5.5.
4. Download vSphere 6.5 components https://my.vmware.com/web/vmware/downloads: Download the vCenter Appliance or vCenter for Windows based on the platform decision that you have arrived at. Here is what you will need to download:
   • VMware vSphere Hypervisor (ESXi ISO) with VMware Tools
   • VMware vCenter and modules for Windows (ISO) or VMware vCenter Server Appliance (ISO)