Administration

Table Of Contents
Table 21. Concurrent Operations Limits for vCenter Server and View Composer (Continued)
Setting Description
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.
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