When you create Horizon FLEX virtual machines, you must consider the requirements of the client end users.

Horizon FLEX virtual machines are restricted virtual machines, meaning that not all functions are available to your client end users. By using policies and entitlements, you can control the features available to client end users. See Creating Policies and Entitlements. Note that client end users can create their own non-Horizon FLEX virtual machines by using the Horizon FLEX client software.

Horizon FLEX Server and Client Compatibility

If you use different versions of the Horizon FLEX server and the Horizon FLEX client, the server and client might become unsynchronized. The following considerations apply to Horizon FLEX server and client compatibility:

  • A client with an earlier Horizon FLEX client version cannot download a virtual machine from the current Horizon FLEX server version. The client is also unable to power on an existing virtual machine in online mode. The client user receives an error message that the client version needs to be upgraded.

    For example, a client using a Horizon FLEX 1.6 client version cannot download a virtual machine from a Horizon FLEX 1.7 server.

  • The current Horizon FLEX client version can work with an earlier Horizon FLEX server version, but the new features of the current server version are not available .

    For example, a client using Horizon FLEX 1.7 can work with a Horizon FLEX 1.6 server. However, any new features in Horizon FLEX 1.7 are not available to an administrator that uses the Horizon FLEX 1.6 server.

  • To prevent compatibility issues, when you upgrade the Horizon FLEX server version, upgrade the client version first. If you upgrade the server before the clients, the clients may not be able to connect to the server until they are upgraded.

Horizon FLEX Virtual Machine Hardware Compatibility

Hardware version incompatibility can prevent client users from opening Horizon FLEX virtual machines. A client running an earlier Horizon FLEX version that does not support later hardware versions cannot open a virtual machine running a higher hardware version.

For example, if a hardware version 12 virtual machine is created by using a Horizon FLEX 1.7 client , a Horizon FLEX 1.5 client cannot open the virtual machine. Because the Horizon FLEX 1.5 client only supports up to hardware version 11, the client cannot open or power on a hardware version 12 virtual machine.

Virtual Processor and Memory Requirements

When you create source virtual machines, Horizon FLEX assumes that the end user host has the same hardware resources as the system you are using. By default, the number of virtual processors and memory size of a Horizon FLEX virtual machine are optimized to fit the end client's host operating system. This setting ensures that the virtual machine is not oversubscribed on the client end user host. For more information, see Optimizing Virtual Processors and Memory for Horizon FLEX Virtual Machines.

If you disable virtual processor and memory size optimization, Horizon FLEX virtual machines must meet the following requirements:

  • The number of virtual processor cores cannot exceed the maximum number of logical CPUs supported by the guest operating system.

  • The number of sockets cannot exceed the maximum number of sockets that the guest operating system supports. If you create the source virtual machine by using Fusion Pro, you cannot specify the number of sockets.

  • The memory size cannot be lower than the minimum memory size that the guest operating system requires.

  • When you use Fusion Pro or Workstation Pro software, the total number of virtual processors cannot exceed the maximum number of virtual processors that Fusion Pro or Workstation Pro supports for the specific guest operating system.

    In the Workstation Pro user interface, the virtual processors and sockets of a virtual machine have the following user interface settings:

    • "Number of processors" indicates the number of (virtual) CPUs, which equals the number of (virtual) sockets.

    • "Number of cores per processor" indicates the virtual processor cores per processor.

    • "Total processor cores" indicates the number of sockets times the number of cores per socket.

    In the Fusion Pro user interface, "Processors" indicates the number of sockets times the number of cores per socket.

    On the host operating system the number of logical CPUs or logical processors is the total number of physical CPUs or sockets times the number of physical cores per CPU, times the number of hyper-threading per physical cores.