The vSphere HA agent on a host is in the Initialization Error state for a minute or more. User intervention is required to resolve this situation.

Problem

vSphere HA reports that an agent is in the Initialization Error state when the last attempt to configure vSphere HA for the host failed. vSphere HA does not monitor the virtual machines on such a host and might not restart them after a failure.

Cause

This condition most often indicates that vCenter Server was unable to connect to the host while the vSphere HA agent was being installed or configured on the host. This condition might also indicate that the installation and configuration completed, but the agent did not become a primary host or a secondary host within a timeout period. Less frequently, the condition is an indication that there is insufficient disk space on the host's local datastore to install the agent, or that there are insufficient unreserved memory resources on the host for the agent resource pool. Finally, for ESXi 5.x hosts, the configuration fails if a previous installation of another component required a host reboot, but the reboot has not yet occurred.

Solution

When a Configure HA task fails, a reason for the failure is reported.
Reason for Failure Action
Host communication errors Resolve any communication problems with the host and retry the configuration operation.
Timeout errors Possible causes include that the host crashed during the configuration task, the agent failed to start after being installed, or the agent was unable to initialize itself after starting up. Verify that vCenter Server is able to communicate with the host. If so, see vSphere HA Agent Is in the Agent Unreachable State or vSphere HA Agent is in the Uninitialized State for possible solutions.
Lack of resources Free up approximately 75MB of disk space. If the failure is due to insufficient unreserved memory, free up memory on the host by either relocating virtual machines to another host or reducing their reservations. In either case, retry the vSphere HA configuration task after resolving the problem.
Reboot pending If an installation for a 5.0 or later host fails because a reboot is pending, reboot the host and retry the vSphere HA configuration task.