Problem:

Sometimes you will face an error while patching your esxi servers using VMware Update Manager(VUM). When you try to remediate your esxi host you get the error message:

“The operation is not supported on the selected inventory objects. Check the events for the objects selected for the operation”

Further when you check the event logs you will find following entry:

“cannot remediate host because it is part of HA Admission Control enabled Cluster”

You can also check logs on your VUM server.The log file is vmware-vum-server-log4cpp.log and is located at :

C:\Documents and Settings\All Users\Application Data\VMware\Update Manager

or

C:\Users\All Users\VMware\VMware Update Manager\Logs

you see an error similar to:

“[DATE’VciHostRemediateTask.VciHostRemediateTask{14}’ 2276 INFO]  [vciHostRemediateTask, 1313] Skipping [HostName] as it is part of HAC enabled cluster”

Cause:

This issue occurs because the admission control policy that has been set is preventing Update Manager from remediating the host.

vCenter Server uses admission control to ensure that sufficient resources are available in a cluster to provide failover protection and to ensure that virtual machine resource reservations are respected.

Admission control imposes constraints on resource usage and any action that would violate these constraints is not permitted. If an automated process needs to take actions, it might temporarily violate the failover constraints. For example, as part of an upgrade directed by VMware Update Manager.

Solution:

Before starting patching of your Esxi Servers that are part of the HA Cluster, make sure you disable “Admission Control” till the time when patching and rebooting of Esxi servers are completed.Once you patched all the servers you can re-enable Admission Control on your cluster.

Steps to disable Admission Control”

1: Right-click the cluster and click Edit Settings.

2: Under Cluster Features, click VMware HA.

3: Under Admission Control, select Disable: Power on VMs that violate availability constraints.

4: Click OK.

Posted in: Vmware.
Last Modified: January 12, 2017

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