Horizon provides high-level guidelines that can help you determine how much storage an instant-clone desktop pool requires.

During the instant clone pool creation process, Horizon displays a storage-sizing table with the free space on the datastores that you select for storing OS disks. You can decide which datastores to use by comparing the actual free space with the estimated requirements for the desktop pool. The formulas used in the table only provide a general estimate of storage use. The clones' actual storage growth depends on many factors:

  • Amount of memory assigned to the golden image.
  • Size of the guest operating system's paging file.
  • Workload on the desktop machines, determined primarily by the types of applications that users run in the guest operating system.
Note: In a deployment that includes hundreds or thousands of clones, configure your desktop pool so that particular sets of datastores are dedicated to particular ESXi clusters. Do not configure pools randomly across all the datastores so that most or all ESXi hosts must access most or all LUNs.

When too many ESXi hosts attempt to write to the OS disks on a particular LUN, contention problems can occur, degrading performance and interfering with scalability. For more information about datastore planning in large deployments, see the Horizon Architecture Planning document.