View provides high-level guidelines that can help you determine how much storage an instant-clone or linked-clone desktop pool requires. A table in the Add Desktop Pool wizard shows a general estimate of the desktop pool's storage requirements.
The storage-sizing table also displays the free space on the datastores that you select for storing OS disks, View Composer persistent disks (for View Composer linked clones only), and replicas. You can decide which datastores to use by comparing the actual free space with the estimated requirements for the desktop pool.
The formulas that View uses can only provide a general estimate of storage use. The clones' actual storage growth depends on many factors:
Amount of memory assigned to the parent virtual machine
Frequency of refresh operations (for View Composer linked clones only)
Size of the guest operating system's paging file
Whether you redirect paging and temp files to a separate disk (for View Composer linked clones only)
Whether you configure separate View Composer persistent disks (for View Composer linked clones only)
Workload on the desktop machines, determined primarily by the types of applications that users run in the guest operating system
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 7 Architecture Planning document.