The goal of this chapter is to help you understand and execute the process of upgrading your core vSphere infrastructure to VMware vSphere 6.5. The core includes your ESXi Hypervisor, vCenter Server, and vCenter Server's components. The upgrade of the third layer products that leverage the core vSphere infrastructure, such as vCloud Director and VMware Horizon View, are not covered in this chapter as they are beyond the scope and purpose of this book.

Before we begin, let me introduce you to the core infrastructure components that will be upgraded:

• VMware vCenter Server: The viability of an upgrade or the need for a new build will depend on the current version of vCenter and the supported upgrade path.
• vCenter Single Sign-On: These are authentication components. They will come into the picture if you are upgrading from vSphere 5.5 to 6.5.
• vCenter Inventory Service: This is no longer a separate service in vCenter 6.5.
• vSphere Web Client: This can be upgraded if the current version is 5.5; if not, it will be a new installation of this component.
• vSphere Platform Service Controller (PSC): If you are upgrading from vSphere 6.0 to 6.5, you will need to review the current deployment model and apply an apt strategy to upgrade PSC.
• vSphere Update Manager: VUM should be updated to the latest version before it can be used to upgrade ESXi hosts managed by the vCenter VUM is integrated with. VUM components are now built-in to the vCenter Appliance.
• vSphere Auto Deploy: This is a requirement to upgrade vSphere Auto Deploy to the same version of vCenter Server.
• VMware ESXi: This can be upgraded by booting the server using the ISO image, using vSphere Update Manager, or updating the image profile if the existing servers are auto-deployed.

The following components form the foundation of vSphere 6.5 environment and its management:

• Hypervisor: VMware ESXi 6.5
• Core management layer: VMware vCenter Server 6.5
• Authentication and core services layer: VMware Platform Services Controller
• Upgrade and patch management layer: VMware Update Manager 6.5

As the whitepaper introduces the components pretty neatly, we will not be doing the same in this book. This book will introduce you to the new changes in the respective chapters.

Unlike the previous releases wherein although the appliance was a neater solution, it still lacked something in terms of features and functionalities. Not every aspect of the vSphere management element layer was integrated into the appliance, but that is about to change with vSphere 6.5. VMware vCenter 6.5 Appliance (vCenter Server Virtual Appliance (vCSA)) is the new king. It has features that are not available with the Windows version of vCenter. Features such as Native High Availability (NHA) and Native Backup and Restore (NBR) are only available with the appliance version of vCenter Server. We will cover NHA and NBR in Chapter 2, Greenfield Deployment of vSphere 6.5.

One component that always stayed out of the box was vCenter Update Manager (VUM). It was always required to have it installed on a Windows machine. VUM is now available as a component integrated into vCSA.

The vCSA Management has also been greatly improved, especially providing more insight into the built-in PostgreSQL database and its usage. VMware is slowly moving away from its dependence on Microsoft SQL and Oracle database instances.

VMware has bundled the essential services, such as the Single Sign-On (SSO), Inventory Service, and certificate management, into a single manageable solution named the Platform Services Controller (PSC). The PSC can be installed on the same machine as the vCenter, installed on a separate supported Windows machine, or run as an integrated component of the vCSA. Refer VMware KB Article 2147672 for supported topologies(https://kb.vmware.com/s/article/2147672).

SSO is an authentication gateway, which takes the authentication requests from various registered components and validates the credential pair against the identity sources added to the SSO server. The components are registered to the SSO server during their installation. We will delve deeper into PSC, and its components in Chapter 2, Greenfield Deployment of vSphere 6.5.

vCenter Update Manager (VUM) is a solution that is used to upgrade or patch your vSphere environment. Keep in mind though that it can only be used to patch/upgrade ESXi hosts and perform some additional tasks, such as VMware tools and virtual machine hardware upgrade. Starting with vSphere 6.5, VUM is no longer required to be installed on Windows machines. It is now fully integrated into the vCenter Appliance and is enabled by default. Also, its reliance on the vSphere C#-based client has been removed. It can now be fully operated using the vSphere Web Client. You will learn more about VUM in Chapter 14, Upgrading and Patching Using vSphere Update Manager.

A vSphere upgrade will require careful assessment of the existing infrastructure. You will need to ensure that the server hardware is compatible with ESXi 6.5. If the existing infrastructure has vCenter components on Microsoft Windows, then you will need to verify whether the current Windows Servers versions are supported for the installation of vCenter 6.5 and its components. If the existing environment has other third layer components, such as the VMware NSX, vRealize Automation, vRealize Operations Manager, vCenter Site Recovery Manager, then it becomes essential to verify whether upgrading the core vSphere components will leave the third layer components unsupported/incompatible. In this section of the chapter, you will learn how to check the hardware compatibility of the existing server hardware, check Windows Server operating system compatibility with the vSphere 6.5 components, and verify third layer product interoperability with the core vSphere 6.5 management components. We will also review various upgrade paths available based on the existing vSphere environment's version and deployment models.

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.

3. 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.
4. 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.
5. 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.
6. 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)

The chances of successfully upgrading your vSphere environment without affecting the supportability and compatibility of your existing components will completely depend on how you plan and execute the upgrade. Once you have taken care of the hardware and software dependencies discussed in this section, you can safely execute the upgrade scripts to perform the upgrade. We will cover vSphere 5.5 to 6.5 and vSphere 6.0 to 6.5 upgrades in separate sections.

vSphere 5.5 is the oldest supported version of an upgrade to vSphere 6.5. Before we begin, let's review vSphere 5.5 component architecture so that we have a clear understanding of what needs to be upgraded. vSphere 5.5 had separate components.

If you have environments running versions older than vSphere 5.5, you will either need to update the components to vSphere 5.5 first or perform a fresh installation of vSphere 6.5 and then move the workloads to the new environment. In such cases, it is quite possible that the older hardware is no longer supported to host vSphere 6.5 or its components. Use the steps provided in the Planning vSphere upgrade section to review your current environment.

In this section, we will cover the steps involved in upgrading a vSphere 5.5 environment to vSphere 6.5:

1. Backup the current configuration: Take snapshots of SSO, vCenter, and database VM before you start the upgrade. Also, take backups of the database if vCenter is running on a physical machine and using an external database.
2. Upgrade SSO servers to vSphere 6.5 PSC: Regardless of the platform (Windows or vCSA), the Single Sign-On component servers should be upgraded from 5.5/6.0 to vSphere 6.5 before the vCenter upgrade.
3. Upgrade vCenter to VCSA 6.5: For instructions on how to migrate from Windows to VCSA 6.5, read the section Upgrading vCenter Server - Migrating from Microsoft Windows to VCSA of this chapter. Single Sign-On and other services will be migrated. vCenter 6.5 can also be installed on a Windows Server, so upgrading vCenter can also be performed without having to rebuild a new machine. Read the section Upgrading vCenter Server on Microsoft Windows for instructions. In either case, a database upgrade will be performed.

4. Upgrade vSphere Update Manager: VUM will be upgraded and made part of the vCenter Server if the current vCenter system being upgraded also has VUM installed on it. If VUM is installed on a separate machine, which is mostly the case in enterprise infrastructures, then you will need to run the vCenter Migration Assistant on the VUM machine as well.
5. Use vSphere Update Manager to upgrade the hosts to ESXi 6.5: Read the Chapter 14, Upgrading and Patching using vSphere Update Manager for instructions on how to use VUM to upgrade ESXi hosts by scheduling upgrades/updates.
6. Use vSphere Update Manager to upgrade the virtual machine hardware and VMware tools: Read Chapter 14, Upgrading and Patching using vSphere Update Manager, for instructions.

When you upgrade from vSphere 5.5 to vSphere 6.5, you start with upgrading all the SSO instances. When the SSO instances are upgraded, the existing vSphere 5.5 environment will remain unaffected and will also be accessible via the already existing instance of the vSphere Web Client. If the existing SSO is not embedded, then the upgrade will result in a separate vSphere 6.5 PSC instance. The result remains the same regardless of the platform vCenter is deployed on. If you have more than one vCenter server connecting to the same SSO domain, then post the upgrade of one of the vCenter Servers, the newer vSphere Web Client 6.5 can be used to view/manage both vSphere 6.5 and 5.5 vCenter Servers. If you have more than one SSO/PSC servers, then upgrading one among them will not affect any of the services including vCenter Servers, except for the linked mode configuration, which will not be able to link two disparate vCenter versions.

Another important aspect to keep in mind is that the Platform Services Controller (PSC) and vCenter Server (Appliance or Windows) will manage two separate sets of services. The following table lists some of the services managed by both the components:

vCenter 6.5 can be installed on a supported Microsoft Windows Server operating system. Therefore, it is possible to upgrade your existing Windows-based vCenter 5.5/6.0 to 6.5. Before we cover the steps involved in the upgrade, we will review the hardware and software requirements for vCenter 6.5:

• Hardware requirements: It is important to make sure that the current system (physical/virtual) hosting the vCenter Server meets the hardware requirements for vCenter 6.5 as laid out by VMware. You should also take into account the growth factor, regarding the number of ESXi hosts and VMs that you expect to manage shortly. To start with, if the upgrade requires you to form an external Platform Service Controller, you will need a machine with at least two CPUs/vCPUs and 4 GB of memory. And the vCenter Server regardless of it using an embedded/external PSC the hardware requirement remains the same; it starts at two CPUs/vCPUs and 10 GB of memory up to 24 CPUs/vCPUs and 48 GB of memory. Storage space requirements for vCenter regardless of using an embedded or external PSC is the same, 17 GB (Program Files, ProgramData, and System folder) and 4 GB (Program Files, ProgramData, and System folder) for an external PSC. The storage space requirement will sometimes have to be reviewed if you plan to host ProgramData and Program Files folders separately for VMware components on a different Windows drive ( sometimes, on a separate VMDK).

• Software requirements: Because you are upgrading from an older version of vCenter, it is possible that Windows Server version compatibility has changed for the newest version. Use the VMware Knowledge Base article (https://kb.vmware.com/s/article/2091273) to review the list of the supported operating systems. In this case, if you are upgrading from 5.5 or higher, you might already be running on a supported Windows Server operating system. Needless to say, it is important to verify before you proceed with the upgrade.

The following procedure will walk you through the steps required to perform an in-place upgrade of vCenter and its components using the vCenter installer:

1. At first, download the latest version of vCenter 6.5 Windows ISO and map it to the machine running the current version of vCenter 5.5/6.0.
2. Browse the contents of the ISO and run the autorun.exe file as a local system administrator or with a user that has local system administrator rights, to bring up the vCenter installer.
3. On the vCenter installer screen, click on the Install button to start the installation wizard.
4. On the Welcome to VMware vCenter Server 6.5 Installer screen, click on the Next button to continue.
5. Accept the EULA and click on the Next button to continue.
6. On the vCenter Single Sign-On and vCenter Credentials screen, supply the SSO administrator password and click on the Next button to let the installer run the pre upgrade checks.
7. On the Configure Ports screen—you are not allowed to make any changes. Click on the Next button to continue.
8. On the Upgrade Options screen, you can choose to migrate all or some of the historical data and the configuration or just the configuration. Choose an intended option and click on the Next button to continue:

9. On the Destination Directory screen, you can choose to change the Program Files and ProgramData locations for this installation. You can also choose to modify the location of the export folder, which is used by the installer to export current configuration. Make intended changes and click on Next to continue.
10. On the next screen, you can choose either join or not join VMware's Customer Experience Improvement Program. Make an intended selection and click on Next to continue.
11. On the Ready to Upgrade screen, confirm that you have backed-up your vCenter Server by selecting the checkbox I verify that I have backed up this vCenter Server machine and click on the Upgrade button.
12. The installer will now perform the upgrade, and if successful, it will display a Setup Completed wizard screen, where you click on Finish to close the wizard:
13. Once done, you should be able to log in to the Web Client to view and manage the upgraded vCenter Server. If everything looks good, you can delete the export folder to free up some disk space.

The installer will remove the older components, import the data, and perform a new installation of vCenter 6.5 and its components. The amount of time the upgrade would take to finish successfully is very dependent on the amount of data that needs to be imported into the new installation and don't be surprised if the upgrade runs for more than 30-40 minutes. Once the installation is complete, you will be able to access vCenter 6.5 using vSphere Web Client. If there is more than one vCenter to upgrade, the procedure remains the same. However, the vSphere 6.5 Web Client would still let you view and manage the older version of vCenter.

To upgrade and migrate vCenter 5.5/6.0 components running on Windows Servers, vCenter 6.5 comes with a new tool named the vCenter Migration Assistant. The procedure to run the migration-assistant is the same whether you are trying to upgrade an external SSO, PSC, or Update Manager or an embedded version of these. The migration-assistant should be run on the machines hosting these services separately, before initiating the vCenter Migration/Upgrade. The migration/upgrade process will migrate data from all the components server with an active migration-assistant session.

The following procedure will walk you through the steps involved in running the vCenter Migration Assistant to enable the migration of configuration and performance data to the appliance:

1. Mapping the VCSA 6.5 ISO to the machine running the Windows-based version of vCenter 5.5/6.0.
2. Browse the ISO ROM contents and navigate to the migration-assistant folder. Copy the entire folder to a location on your Windows-based vCenter machine:

3. Browse the contents of the migration-assistant from the hard drive location and run the executable VMware-Migration-Assistant.exe as an administrator:

4. This will bring up a Windows CLI interface, and you will be prompted for the SSO administrator password. Type in the password and press Enter. You will also be prompted for service account credentials if the vCenter Server Windows service is run with a service account's privileges. Type in the password and press Enter:

5. You will now see the migration-assistant running prechecks and eventually warn you about extension/plugins that cannot be upgraded using this process. For instance, I have got an SRM plugin that cannot be upgraded. It will also display the source vCenter's configuration, and the expected resultant configuration post a successful upgrade:

6. There is nothing more to do with the migration-assistant tool at this point, but do not close it.
7. You are now all set to run the VCSA installer's Migrate or Upgrade wizards.

VMware with the release of vSphere 6.5 will now let you migrate an existing vCenter Server Windows installation, be it vCenter 5.5 or 6.0, to vCenter Server Appliance 6.5. This form of migration will let you move from any deployment model (embedded or external SSO/PSC) and any external database (Microsoft SQL, SQL Server Express, or Oracle). All the database contents will be migrated to an embedded PostgreSQL database within the appliance. Keep in mind that although it allows moving from any topology, it does not allow modifying the topology while migrating.

Virtual machine requirements, there are no operating system level requirements because this is an appliance and VMware is using the JeOS (Just Enough Operating System) version of Linux named the Photon OS with all the required libraries bundled.

However, it is important to understand the sizing requirements. The compute requirements for VCSA are similar to that of a Windows installation. If the upgrade requires an external Platform Service Controller, you will need a machine with at least two CPUs/vCPUs and 4 GB of Memory. Starting with two CPUs/vCPUs and 10 GB of memory up to 24 CPUs/vCPUs and 48 GB of memory, the compute requirements for the vCenter Server remains the same regardless of the type of database configured - embedded or external. The virtual machine storage requirements are stated slightly differently, though. If deployed alone, PSC will require 60 GB of storage space. For more details on the requirements, refer to the VMware vSphere 6.5 Upgrade Guide.

To perform this migration, you will need access to the vCenter Server Appliance 6.5 ISO downloaded from https://my.vmware.com/web/vmware/downloads. Also, because this will deploy a new appliance virtual machine, you will need to decide on the following factors:

• Placement location: This is is the vCenter inventory location where you would like to place the VCSA VM. The location could be a cluster, a resource pool or just a VM folder.
• Datastore: You will need to decide on an appropriate datastore to store the appliance.

The following procedure will walk you through the steps involved in migrating and upgrading a vCenter 5.5/6.0 installation to a vCenter Server 6.5 Appliance with an embedded database:

1. Use the migration-assistant to perform the pre-checks and ready the source vCenter Server and its component servers for migration. Read the section Using the vCenter 6.5 Migration Assistant of this chapter for instructions.
2. Once you have readied the vCenter and its components using migration-assistant, map the VCSA ISO to a non-vCenter machine because the source will be shut down during the migration.

3. At the non-vCenter machine, browse the contents of the VCSA ISO ROM, navigate to vcsa-ui-installer, and choose a subdirectory corresponding to your operating system (lin64, mac, and win32). In this case, we will navigate to the win32 directory and run the executable installer.exe as an administrator to bring up the vCenter Server Appliance 6.5 Installer window:

4. On the vCenter Server Appliance 6.5 Installer wizard window, click on Migrate to bring up the Migrate - Stage 1: Deploy appliance window. Click on Next to continue.
5. Click on the Migrate - Stage 1: Deploy appliance window and then click on Next to continue.

6. Accept the EULA and click on Next to continue.
7. Supply the source Windows vCenter's FQDN/IP and the SSO administrator's password to proceed further:

8. Click on Yes to accept the source vCenter Server's SSL certificate.

9. Supply the FQDN/IP and the credentials of the vCenter Server or ESXi host to deploy the VCSA VM:

10. Click on Yes to accept the vCenter/ESXi SSL certificate.
11. Select a datacenter or VM folder from the destination vCenter inventory and then click on Next:

12. Select a cluster or a host from the vCenter inventory to deploy the VCSA VM and Click on Next to continue:

13. Supply VM name for the VCSA Appliance and set the Root password. Click on Next to continue.

14. Choose an intended VCSA Deployment size and Storage size. Click on Next to continue:

15. Select a datastore for the VCSA VM and click on Next to continue:

16. Choose a port group and a temporary static IP configuration, which will enable the appliance VM to communicate with the source vCenter and migrate configuration and other data:

17. On the Ready to complete stage 1 screen, review the settings and click on Finish to start the deployment:

18. Once the deployment is complete, click on Continue to proceed to the stage-2 of the deployment process. Stage-2 is where you let VCSA VM connect to the source vCenter and initiate the data migration.
19. On the Migrate - Stage 2 screen, click on Next to continue.

20. You will be prompted with the same set of warnings generated by the migration-assistant. Click on Close to continue.
21. The wizard will prompt you to join the same Active Directory domain as the source vCenter. Supply the credentials of an Active Directory user with the permissions to join a machine to the domain and click on Next:

22. On the Select migration data screen, you can choose to migrate all or some of the historical data and the configuration or just the configuration. Select an intended option and click on Next to continue:

23. Choose to either join or not join the VMware CEIP and click on Next to continue.
24. On the Ready to complete screen, review the settings and confirm that you have backed-up your vCenter Server by selecting the checkbox I have backed up the source vCenter Server and all the required data from the database and click on Finish to start the migration and configuration of the VCSA:

25. You will be warned about the fact that the source vCenter will be shut down during this process. Click on OK to acknowledge and continue.
26. The data migration will begin, and once done, it will shut down the source vCenter and configure the appliance VM.
27. Once the process completes successfully, click on Close.
28. You should now be able to login to the vSphere Web Client or the new HTML client to view and manage the new vCenter.

The migration process deploys a vCSA Appliance and imports the data from the vCenter windows installation. It retains vCenter Server's IP address, UUID, hostname, SSL certificates, and management object reference IDs; therefore once the installation is complete, the vCenter Server Windows machine is shutdown. If for any reason the upgrade fails and the vCenter Windows machine is shut down, all you need to do is to power-off the VCSA VM and power-on the vCenter Windows machine. The upgrade and migrate process will not make any changes to the source Windows machine.

An existing vCenter 5.5/6.0 Appliance can be upgraded to VCSA 6.5. This is done using the upgrade wizard of the vCenter Appliance installer. An upgrade does not change the current deployment model; if the vCSA is accompanied by external SSO/PSCs, then they will need to be upgraded first. The upgrade procedure is the same for both vCSA and PSC appliances.

If the vSphere 5.5/6.0 environment has any of its component, running on Windows Server, then the migration-assistant should be run to ready those component servers. Read the instructions in the section Using the vCenter 6.5 Migration Assistant.

The following procedure will guide you through the steps required to upgrade an existing vCSA 5.5/6.0 and its components to VCSA 6.5:

1. Once you have readied the Windows component servers using migration-assistant, map the VCSA ISO to a machine that can be used to reach the source VCSA over the network. The machine used for this purpose can be running Windows, Linux or macOS.
2. Browse the VCSA ISO ROM contents and navigate to vcsa-ui-installer and choose a subdirectory corresponding to your operating system (lin64, mac, win32). In this case, we will navigate to the win32 directory and run the executable installer.exe as an administrator to bring up the vCenter Server Appliance 6.5 Installer window.

3. On the vCenter Server Appliance 6.5 Installer wizard window, click on Upgrade to bring up the Upgrade - Stage 1: Deploy appliance window. Click on Next to continue.
4. Accept the EULA and click on Next to continue.
5. Supply the source VCSA's FQDN/IP and the SSO administrator's password and also the FQDN/IP and the credentials of the vCenter Server or ESXi host managing the source VCSA.
6. Click on Yes to accept the source vCenter Server's SSL certificate.
7. On the Appliance Deployment Target screen, supply the FQDN/IP and the credentials of the vCenter Server or ESXi host to deploy the VCSA VM.
8. Click on Yes to accept the vCenter/ESXi SSL certificate.
9. Supply VM name for the vCSA Appliance and set the Root password.
10. Choose an intended VCSA Deployment size and Storage size. Click on Next to continue.
11. Select a datastore for the VCSA VM and click Next.
12. Choose a port group and a temporary static IP configuration, which will enable the appliance VM to communicate with the source vCenter and migrate configuration and other data.
13. On the Ready to complete stage 1 screen, review the settings and click on Finish to start the VCSA 6.5 deployment.
14. Once the deployment is complete, click on Continue to proceed into the stage-2 of the deployment process. Stage-2 is where you let the VCSA VM connect to the source vCenter and initiate the data migration.
15. On the Upgrade - Stage 2 screen click Next to continue.
16. You will be presented with the pre-upgrade check result. One of the important recommendations/warnings will be to configure your destination cluster's DRS automation level to manual. This is to make sure that the appliance VM is not being moved around by DRS during the upgrade process. Click on Close to continue.
17. On the Select migration data screen, you can choose to migrate all or some of the historical data and the configuration or just the configuration. Select an intended option and click on Next to continue.
18. Choose to either join or not join the VMware CEIP and click on Next to continue.
19. On the Ready to complete screen, review the settings and confirm that you have backed-up your vCenter Server by selecting the checkbox I verify that I have backed up this vCenter Server machine and click on Finish to start the migration and configuration of the VCSA.

20. You will be warned about the fact that the source vCenter will be shut down during this process. Click on OK to acknowledge and continue.
21. The data migration will begin, and once done, it will shut down the source vCenter and configure the appliance VM.
22. Once the process completes successfully, click on Close.
23. You should now be able to log in to the Web Client to view and manage the new vCenter.

Once you have vCenter Server upgraded to version 6.5, the next step is to upgrade the ESXi hosts. The upgrade procedure will depend on the current deployment architecture. For instance, if all your ESXi hosts were deployed using the VMware Auto Deploy server, then you'll have to update the image profile sourcing the streamed image using a new offline bundle. As Auto Deploy is covered in Chapter 5, Using vSphere Auto Deploy, in this chapter, we will cover the upgrade of the ESXi host using the installation media. VMware ESXi can also be upgraded by running the ESXi installer on each of the servers or use vSphere Update Manager to perform the same activity. You will learn about patching/upgrading ESXi hosts using VUM in Chapter 14, Upgrading and Patching using vSphere Update Manager.

Before you begin any upgrade, it is very important to plan for it. So what would you need to do to perform an upgrade of ESXi? You would, of course, need the ISO image downloaded from VMware's website, but you would also need a method to present the ISO to the physical machine so that it can boot from it. Most of the modern server equipment's have a methodology to avoid the need to burn ISO to a physical DVD medium and then insert it into the DVD drive of the physical machine. If you are an administrator, you might already be aware of terms such as ILO (HP), DRAC (Dell), and KVM Manager (Cisco). These are web-based tools that will connect to an RAC on the server and enable remote access to the server's console via the Web. Enough said on what is available out there; let's make a list of what you need to begin the upgrade:

• The ESXi 6.5 Hypervisor ISO image can be downloaded from VMware's downloads page https://my.vmware.com/web/vmware/downloads
• Access to the remote console of the server on which the upgrade will be performed

The following procedure will walk you through the steps involved in upgrading ESXi 5.5/6.0 to ESXi 6.5 using the ESXi installer:

1. Boot the host with the ESXi 6.5 installer ISO mapped to it.
2. Choose ESXi 6.5 standard installer from the boot menu and press Enter:

3. Once the installer is fully loaded into the memory, you will be prompted with a Welcome to the VMware ESXi 6.5.0 Installation screen. Now press Enter to continue.
4. To accept the EULA and continue, press the function key F11.
5. Select the storage device that has the previous installation of ESXi and press F1 to view the disk details:

6. On pressing F1, it will show you the Disk Details. In this case, it has detected an ESXi 6.0 installation. Press Enter to go back to the Select a Disk to Install or Upgrade screen:

7. At the Select a Disk to Install or Upgrade window, press Enter to continue.
8. On the ESXi and VMFS Found window, select the option Upgrade ESXi, preserve VMFS datastore and press Enter to continue:

9. On the Confirm Upgrade window, select the Upgrade option by pressing the F11 key:

10. If the upgrade completes successfully, you will be presented with an Upgrade Complete success window. Now press Enter to reboot the ESXi host.
11. After a reboot, you should be able to see the ESXi 6.5 DCUI welcome screen.

You should now be able to connect to this vCenter using the embedded host client as well. If the host was managed by a vCenter, then the inventory should now show this ESXi host connected.

Once you have vCenter and Update Manager upgraded and configured for use, the ESXi host upgrades can be performed using VUM in a much more effective manner. You will be able to run the upgrades simultaneously on more than one ESXi host using VUM remediation. You will learn more about this in Chapter 14, Upgrading and Patching using vSphere Update Manager.