5.2

Table Of Contents
n
You can deploy a desktop pool on a cluster that contains up to 32 ESXi hosts, with certain restrictions.
Replica disks must be stored on VMFS5 or later datastores or NFS datastores. If you store replicas on a
VMFS version earlier than VMFS5, a cluster can have at most eight hosts. OS disks and persistent disks
can be stored on NFS or VMFS datastores.
Reducing Storage Requirements with View Composer
Because View Composer creates desktop images that share virtual disks with a base image, you can reduce
the required storage capacity by 50 to 90 percent.
View Composer uses a base image, or parent virtual machine, and creates a pool of up to 2,000 linked-clone
virtual machines. Each linked clone acts like an independent desktop, with a unique host name and IP address,
yet the linked clone requires significantly less storage.
Replica and Linked Clones on the Same Datastore
When you create a linked-clone desktop pool, a full clone is first made from the parent virtual machine. The
full clone, or replica, and the clones linked to it can be placed on the same data store, or LUN (logical unit
number). If necessary, you can use the rebalance feature to move the replica and linked clones from one LUN
to another.
Replica and Linked Clones on Different Datastores
Alternatively, you can place View Composer replicas and linked clones on separate datastores with different
performance characteristics. For example, you can store the replica virtual machines on a solid-state drive
(SSD). Solid-state drives have low storage capacity and high read performance, typically supporting tens of
thousands of I/Os per second (IOPS). You can store linked clones on traditional, spinning media-backed
datastores. These disks provide lower performance, but are less expensive and provide higher storage capacity,
which makes them suited for storing the many linked clones in a large pool. Tiered storage configurations can
be used to cost-effectively handle intensive I/O scenarios such as simultaneous rebooting of many virtual
machines or running scheduled antivirus scans.
For more information, see the best-practices guide called Storage Considerations for VMware View.
Disposable Disks for Paging and Temp Files
When you create a linked-clone pool, you can also optionally configure a separate, disposable virtual disk to
store the guest operating system's paging and temp files that are generated during user sessions. When the
virtual machine is powered off, View Manager deletes the disposable disk. Using disposable disks can save
storage space by slowing the growth of linked clones and reducing the space used by powered off virtual
machines.
Persistent Disks for Dedicated Desktops
When you create dedicated-assignment desktop pools, View Composer can also optionally create a separate
persistent virtual disk for each virtual desktop. The end user's Windows profile and application data are saved
on the persistent disk. When a linked clone is refreshed, recomposed, or rebalanced, the contents of the
persistent virtual disk are preserved. VMware recommends that you keep View Composer persistent disks on
a separate datastore. You can then back up the whole LUN that holds persistent disks.
Local Datastores for Floating, Stateless Desktops
Linked-clone desktops can be stored on local datastores, which are internal spare disks on ESXi hosts. Local
storage offers advantages such as inexpensive hardware, fast virtual-machine provisioning, high-performance
power operations, and simple management. However, using local storage limits the vSphere infrastructure
configuration options that are available to you. Using local storage is beneficial in certain View environments
but not appropriate in others.
Chapter 3 Managing Desktop Pools from a Central Location
VMware, Inc. 29