Upgrading an enterprise Horizon 7 deployment involves several high-level tasks. Upgrading is a multistage process in which procedures must be performed in a particular order. You upgrade View Composer before upgrading Horizon Connection Server and the other Horizon 7 servers.
During an upgrade, Horizon 7 does not support View Composer provisioning and maintenance operations. Operations such as provisioning and recomposing linked-clone desktops are not supported during the transitional period when any Horizon 7 servers are still running the earlier version. You can successfully perform these operations only when all instances of Connection Server and View Composer have been upgraded.
You must complete the upgrade process in a specific order. Order is also important within each upgrade stage.
How many of the following tasks you need to complete depends on which components of Horizon 7 you use in your deployment.
- Upgrade the Horizon Client software that runs on end users' client devices. See Upgrade the Client Application.
- On the physical or virtual machines that host View Composer and VMware® vCenter Server™, make backups and temporarily halt certain scheduled tasks. See Preparing vCenter Server and View Composer for an Upgrade.
If you have a standalone View Composer, which is installed in a separate machine from vCenter Server, you need only make a backup of the View Composer database and the View Composer TLS/SSL certificate. You can schedule an upgrade of vCenter Server separately, if you want to also upgrade vCenter Server.
For details about which versions of Horizon are compatible with which versions of vCenter Server and ESXi, see the VMware Product Interoperability Matrix at http://www.vmware.com/resources/compatibility/sim/interop_matrix.php.
- Upgrade View Composer on the existing host or migrate to a new machine. See Upgrade View Composer.
- On the physical or virtual machines that host Connection Server instances, make backups and record various configuration and system settings. See Preparing Connection Server for an Upgrade.
If you have multiple Connection Server instances in a replicated group, make backups and record configuration settings for only one instance in the group. For other preparation tasks, you can perform the tasks for one instance at a time, just before you perform the upgrade of that server instance.
- Upgrade Connection Server instances that are not paired with security servers. See Upgrade Connection Servers in a Replicated Group.
In a typical production environment that consists of two or more Connection Server instances fronted by a load balancer, you need to remove Connection Server instances from the load balanced cluster while they are upgraded.
Important: After you upgrade a Connection Server instance to the latest version, you cannot downgrade that instance to an earlier version. After you upgrade all Connection Server instances in a replicated group, you cannot add another instance that runs an earlier version. - If you use security servers, make backups and record various configuration and system settings. See Preparing Security Server for an Upgrade.
To minimize down time, you can perform these tasks for one security server at a time, just before you perform the upgrade of that server.
- If you use security servers, upgrade each security server and its paired Connection Server instance. If you upgrade these pairs one by one, removing each security server from the load-balanced group, upgrading the pair, and then adding the security server back to the group, you can achieve zero downtime. See Upgrade Security Servers and Their Paired Connection Servers.
- Upgrade the group policies used in Active Directory. See Using Horizon 7 Group Policy Administrative Template Files.
- If you are also upgrading VMware vSphere components, upgrade vCenter Server. See Upgrade vCenter Server.
During the vCenter Server upgrade, existing remote desktop and application sessions will not be disconnected. Remote desktops that are in a provisioning state will not get powered on during the vCenter Server upgrade, and new desktops cannot be launched and View Composer operations are not allowed during the vCenter Server upgrade.
- If you are also upgrading vSphere, upgrade the VMware® ESXi™ hosts and virtual machines. See Upgrade ESXi Hosts and Their Virtual Machines.
ESXi hosts can be upgraded with zero down time by vMotioning the virtual machines to another host in the cluster, if hosts are configured under clustered environment.
- If you currently use Windows Terminal Services servers as desktop sources, upgrade to Windows Server 2008 R2 or later and verify that the RDS Host role is installed. See Upgrade RDS Hosts That Provide Session-Based Desktops
- Upgrade the Horizon™ Agent or View Agent ™ software that runs on the physical or virtual machines that are used as desktop sources, as full-clone desktops in a pool, and as individual desktops in a manual pool. See Upgrade View Agent or Horizon Agent.
- Use the newly upgraded virtual machine desktop sources to create upgraded pools of desktops. See Upgrade View Composer Desktop Pools.
- If you use the Cloud Pod Architecture feature, see Upgrading a Cloud Pod Architecture Environment.
Because certain commands can simultaneously upgrade more than one stage, VMware recommends that you thoroughly understand the irreversible changes at each stage before you upgrade your production environments.
