This article only covers a sub-set of the entire upgrade sequence across the entire VMware product portfolio.

There can be quite a bit of planning required before you upgrade to vSphere 6.0.

Interoperability: Before starting the upgrade phase of your existing vSphere environment, make note of the following interoperability:

• Any other VMware solutions associated with your environment, such as VMware vCloud Director (vCD) and VMware vCenter Site Recovery Manager (SRM)
• Any other third (3rd) party solutions associated with your environment, such as Backup/Restore applications, Monitoring applications, or any other services that interact.
• Any databases (e.g. Microsoft SQL, Oracle) used with vCenter Server, vSphere Update Manager or any other VMware solutions associated with your environment and the database's current compatibility level. If using a compatibility level with your database, ensure that this level is supported.

Use the following to determine which versions of these VMware solutions are compatible with vCenter Server 6.0 and the sequence in which to upgrade. Additionally, use the following to ensure that the databases used by vCenter Server or any other VMware solutions are running a compatible editions, Versions and Service Packs. Contact your third party vendors in order to ensure that their products will work with vSphere 6.0.

In-place upgrades to vCenter 6.0, vSphere Update Manager 6.0 and ESXi 6.0 are supported for vSphere versions 5.0 and later.

Hardware: Before starting the upgrade phase of your existing vSphere environment, ensure that your hardware is compatible and you are not using any deprecated devices. Use the following to determine if the hardware used in your environment is compatible with ESXi 6.0:

VMware recommends to use the vendor-specific customized ESXi 6.0 ISOs where applicable when upgrading your ESXi hosts as they contain additional or specific drivers for your hardware.

Topology, your vSphere Domain, and VMware Validated Reference Designs (VVRD): Before starting the upgrade phase of your existing vSphere environment, review your vSphere topology. Although upgrade paths are possible and complete successfully, some resulting topologies may not be recommended by VMware. VMware recommends reconfiguring your vSphere domain topology before upgrading to vSphere 6.0. Use the following to determine if your vSphere environment is supported and approved by VMware:

For more information about when to use the external or embedded deployment models see vCenter Server Deployment Models. Some of the services that were deployed independently of vCenter Server are migrated to either vCenter Server or Platform Services Controller during upgrade. For more information about how the vSphere 5.x services map to the new vSphere 6.0 servers, see Migration of Distributed vCenter Server for Windows Services During Upgrade to vCenter Server 6.0.

Microsoft Active Directory Integration: For customers intending to integrate their vSphere environment with their Microsoft Active Directory infrastructure, review your current functionality level.

Important Information and Release Notes: Lastly, before starting the upgrade phase of your existing vSphere environment, review the following documentation on the Release Notes and important information:

Each upgrade from vSphere 5.x to vSphere 6.0 has been custom tailored to match your current environment. The vCenter Server Upgrade wizard will review your existing environment and plan the best path to bring you to vSphere 6.0. For more information about the high-level upgrade workflows, see About the vCenter Server for Windows 6.0 Upgrade Process and About the vCenter Server Appliance 6.0 Upgrade Process. Additionally, use the following information below to understand the upgrade and what to expect.

Refer to the Update sequence for vSphere 6.0 and its compatible VMware products (2109760) in the event that you are unsure of which component to upgrade next within your environment.

Platform Services Controller: This will be the first phase of your upgrade sequence. You will need to either upgrade your existing vCenter Single Sign-On infrastructure or freshly install depending on your current vSphere 5.x version.

For customers using planning a large scale upgrade with multiple vCenter Servers and vCenter Single Sign-On nodes, refer to the Mixed-Version Transitional Environments in vCenter Server for Windows Upgrades which will guide you through the recommended steps.

vCenter Server and vSphere Update Manager: This will be the second phase of your upgrade sequence. You will be upgrading your existing vCenter Server and vSphere Update Manager node(s). See the Upgrading to vCenter Server 6.0 best practices (2109772) for specific hardware and software requirements, upgrade guidance as well as any limitations when upgrading you Windows-based or Appliance-based vCenter Servers.

For the Appliance:

Note: As of vSphere 6.0 Update 1, it is now supported to upgrade your vCenter Server Appliance configured in a distributed topology, with an external vCenter Single Sign-On node.

For Windows:

Virtual Machines: This will be the fourth phase of your upgrade sequence. Ensure that the above sequences have been completed successfully and your underlying infrastructure is stable before starting this phase. Although upgrading VMware Tools and the Virtual Hardware are optional, it is still highly recommended. The extended support is meant to facilitate upgrades and should not be seen as an excuse to avoid upgrading VMware Tools and Virtual Hardware. See the VMware Product Interoperability Matrix and ESXi/ESX hosts and compatible virtual machine hardware versions list (2007240) for VMware Tools and Virtual Hardware interoperability with ESXi 6.0, respectively. VMware recommends to upgrade your vSphere infrastructure, at a minimum, to Virtual Hardware version 10.

VMFS : This will be the fifth phase of your upgrade sequence. Customers that are still using VMFS-3 can continue using these datastores on vSphere 6.0; however, VMware recommends that you upgrade them to VMFS-5 when time allows. Once you have upgraded to VMFS-5, you will no longer be able to mount these datastores to ESXi 4.x hosts. For guidance on reviewing and upgrading your VMFS datastores, see Upgrading VMFS Datastores and Upgrade a Datastore to VMFS5

Review the following documentation after completion to perform house keeping items as well as review documentation for new vSphere components:

New Components and Feature Walkthrough:

Use this section to review the hardware for your environment:

• Determining Network/Storage firmware and driver version in ESXi/ESX 4.x, ESXi 5.x and ESXi 6.x (1027206)
  
• Identifying correct driver for ESXi/ESX host PCI devices (HBA) using VMware Hardware Compatibility Guide (HCL) (1031534)