Recently I ran into an issue where HA triggered on a cluster but failed. This generated an alert on several hundred VMs. Hating to click each one to reset the alarm that wasn’t clearing I found the following solution.

PowerCLI to vCenter Run the following command to disable the alarm Get-AlarmDefinition "vSphere HA virtual machine failover failed" |Set-AlarmDefinition -Enabled:$false The alarm should clear almost instantly for all VMs Re-enable the alarm Get-AlarmDefinition "vSphere HA virtual machine failover failed" |Set-AlarmDefinition -Enabled:$true