Activate Maintenance Mode for a Host on vCenter Server

To complete some specific administration tasks, you might need to activate maintenance mode for a host. On vCenter Server, you can activate maintenance mode by using the Set-VMHost cmdlet.

Prerequisites

Verify that you are connected to a vCenter Server system.

Procedure

1	Save the Host host object as a variable. $vmhost = Get-VMHost -Name Host
2	Get the cluster to which Host belongs and save the cluster object as a variable. $vmhostCluster = Get-Cluster -VMHost $vmhost
3	Start a task that activates maintenance mode for the Host host and save the task object as a variable. $updateHostTask = Set-VMHost -VMHost $vmhost -State "Maintenance" -RunAsync Note If the host is not automated or is partially automated and has powered-on virtual machines running on it, you must use the RunAsync parameter and wait until all powered-on virtual machines are relocated or powered off before applying DRS recommendations.
4	Get and apply the recommendations generated by DRS. Get-DrsRecommendation -Cluster $vmhostCluster | where {$_.Reason -eq "Host is entering maintenance mode"} | Apply-DrsRecommendation
5	Get the task output object and save it as a variable. $myUpdatedHost = Wait-Task $updateHostTask