An administrator enables vSphere High Availability (HA) on an existing cluster with a large number of hosts and virtual machines. The administrator notices that the setup of vSphere HA on some of…

The config.vpxd.das.electionWaitTimeSec advanced vCenter setting controls how long vCenter Server waits for the HA agent master election to finish before declaring a configuration failure. In clusters with a large number of hosts and virtual machines, the election process takes more time because more agents must communicate, and the default wait time may expire prematurely. Increasing this value gives the election process enough time to complete successfully, resolving the setup failures.

The vpxd.das.aamMemoryLimit parameter caps the memory available to the HA agent process and does not affect the master election timeout that causes setup failures in large clusters.

The das.useDefaultIsolationAddress setting controls which IP address an ESXi host pings to determine network isolation and has no bearing on HA agent configuration or election timing.

The das.iostatsinterval parameter sets the frequency at which I/O statistics are sampled for VM Component Protection and is unrelated to HA agent setup or election behavior.