You can place View Composer replicas and linked clones on separate datastores with different performance characteristics. This flexible configuration can speed up intensive operations such as provisioning many linked clones at once or running antivirus scans.

For example, you can store the replica virtual machines on a solid-state disk-backed datastore. Solid-state disks have low storage capacity and high read performance, typically supporting 20,000 I/Os per second (IOPS). View Composer creates only one replica for each View Composer base-image snapshot on each ESX cluster, so replicas do not require much storage space. A solid-state disk can improve the speed at which ESX reads a replica's OS disk when a task is performed concurrently on many linked clones.

You can store linked clones on traditional, spinning media-backed datastores. These disks provide lower performance, typically supporting 200 IOPS. They are cheap and provide high storage capacity, which makes them suited for storing the many linked clones in a large pool. ESX does not need to perform intensive, simultaneous read operations on a linked clone.

Configuring replicas and linked clones in this way can reduce the impact of I/O storms that occur when many linked clones are created at once. For example, if you deploy a floating-assignment pool with a delete-desktop-on-logoff policy, and your users start work at the same time, View Manager must concurrently provision new desktops for them.

Important

This feature is designed for specific storage configurations provided by vendors who offer high-performance disk solutions. Do not store replicas on a separate datastore if your storage hardware does not support high-read performance.

You must follow certain requirements when you store the replica and linked clones in a pool on separate datastores:

You can specify only one separate replica datastore for a pool.

If a replica datastore is shared, it must be accessible from all ESX hosts in the cluster.

If the linked-clone datastores are shared, the replica datastore must be shared. Replicas can reside on a local datastore only if you configure all linked clones on local datastores on the same ESX host.