Architecture Planning

Table Of Contents
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Compatible third-party failover products
IMPORTANT To use one of these failover strategies, the vCenter Server instance must not be installed in a
virtual machine that is part of the cluster that the vCenter Server instance manages.
In addition to these automated options for vCenter Server failover, you can also choose to rebuild the failed
server on a new virtual machine or physical server. Most key information is stored in the vCenter Server
database.
Risk tolerance is an important factor in determining whether to use one or multiple vCenter Server instances
in your pod design. If your operations require the ability to perform desktop management tasks such as
power and refit of all desktops simultaneously, you should spread the impact of an outage across fewer
desktops at a time by deploying multiple vCenter Server instances. If you can tolerate your desktop
environment being unavailable for management or provisioning operations for a long period, or if you
choose to use a manual rebuild process, you can deploy a single vCenter Server instance for your pod.
Frequency of Power, Provisioning, and Refit Operations
Certain virtual machine desktop power, provisioning, and refit operations are initiated only by
administrator actions, are usually predictable and controllable, and can be confined to established
maintenance windows. Other virtual machine desktop power and refit operations are triggered by user
behavior, such as using the Refresh on Logoff or Suspend on Logoff settings, or by scripted action, such as
using Distributed Power Management (DPM) during windows of user inactivity to power off idle ESXi
hosts.
If your View design does not require user-triggered power and refit operations, a single vCenter Server
instance can probably suit your needs. Without a high frequency of user-triggered power and refit
operations, no long queue of operations can accumulate that might cause View Connection Server to time-
out waiting for vCenter Server to complete the requested operations within the defined concurrency setting
limits.
Many customers elect to deploy floating pools and use the Refresh on Logoff setting to consistently deliver
desktops that are free of stale data from previous sessions. Examples of stale data include unclaimed
memory pages in pagefile.sys or Windows temp files. Floating pools can also minimize the impact of
malware by frequently resetting desktops to a known clean state.
Some customers are reducing electricity usage by configuring View to power off desktops not in use so that
vSphere DRS (Distributed Resources Scheduler) can consolidate the running virtual machines onto a
minimum number of ESXi hosts. VMware Distributed Power Management then powers off the idle hosts. In
scenarios such as these, multiple vCenter Server instances can better accommodate the higher frequency of
power and refit operations required to avoid operations time-outs.
Simplicity of Infrastructure
A single vCenter Server instance in a large-scale View design offers some compelling benefits, such as a
single place to manage golden master images and parent virtual machines, a single vCenter Server view to
match the View Administrator console view, and fewer production back-end databases and database
servers. Disaster Recovery planning is simpler for one vCenter Server than it is for multiple instances. Make
sure you weigh the advantages of multiple vCenter Server instances, such as duration of maintenance
windows and frequency of power and refit operations, against the disadvantages, such as the additional
administrative overhead of managing parent virtual machine images and the increased number of
infrastructure components required.
Chapter 4 Architecture Design Elements and Planning Guidelines for Remote Desktop Deployments
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