Administration

Table 2‑1. Concurrent Operations Limits for vCenter Server and View Composer
Setting Description
Max concurrent vCenter
provisioning operations
Determines the maximum number of concurrent requests that View Connection
Server can make to provision and delete full virtual machines in this vCenter Server
instance.
The default value is 20.
This setting applies to full virtual machines only.
Max concurrent power
operations
Determines the maximum number of concurrent power operations (startup,
shutdown, suspend, and so on) that can take place on virtual machines managed by
View Connection Server in this vCenter Server instance.
The default value is 50.
For guidelines for calculating a value for this setting, see “Setting a Concurrent Power
Operations Rate to Support Remote Desktop Logon Storms,” on page 21.
This setting applies to full virtual machines and linked clones.
Max concurrent View
Composer maintenance
operations
Determines the maximum number of concurrent View Composer refresh, recompose,
and rebalance operations that can take place on linked clones managed by this View
Composer instance.
The default value is 12.
Remote desktops that have active sessions must be logged off before a maintenance
operation can begin. If you force users to log off as soon as a maintenance operation
begins, the maximum number of concurrent operations on remote desktops that
require logoffs is half the configured value. For example, if you configure this setting
as 24 and force users to log off, the maximum number of concurrent operations on
remote desktops that require logoffs is 12.
This setting applies to linked clones only.
Max concurrent View
Composer provisioning
operations
Determines the maximum number of concurrent creation and deletion operations that
can take place on linked clones managed by this View Composer instance.
The default value is 8.
This setting applies to linked clones only.
Setting a Concurrent Power Operations Rate to Support Remote Desktop
Logon Storms
The Max concurrent power operations setting governs the maximum number of concurrent power
operations that can occur on remote desktop virtual machines in a vCenter Server instance. This limit is set
to 50 by default. You can change this value to support peak power-on rates when many users log on to their
desktops at the same time.
As a best practice, you can conduct a pilot phase to determine the correct value for this setting. For planning
guidelines, see "Architecture Design Elements and Planning Guidelines" in the View Architecture Planning
document.
The required number of concurrent power operations is based on the peak rate at which desktops are
powered on and the amount of time it takes for the desktop to power on, boot, and become available for
connection. In general, the recommended power operations limit is the total time it takes for the desktop to
start multiplied by the peak power-on rate.
For example, the average desktop takes two to three minutes to start. Therefore, the concurrent power
operations limit should be 3 times the peak power-on rate. The default setting of 50 is expected to support a
peak power-on rate of 16 desktops per minute.
The system waits a maximum of five minutes for a desktop to start. If the start time takes longer, other
errors are likely to occur. To be conservative, you can set a concurrent power operations limit of 5 times the
peak power-on rate. With a conservative approach, the default setting of 50 supports a peak power-on rate
of 10 desktops per minute.
Chapter 2 Configuring View Connection Server
VMware, Inc. 21