When you remove a managed host from a cluster, the cluster loses the resources provided by the removed host, reducing the total capacity. All historical data remains in the vCenter Server database. Before removing a host from a cluster, make sure that the cluster has enough resources to provide to the workloads to avoid performance issues or, in the worst situation, service disruption.
If the vSphere DRS feature is not enabled in the cluster, make sure to migrate all running VMs to a new host using vMotion before putting the host in Maintenance Mode. If not migrated, powered off, or suspended, VMs will remain associated with the removed host:
Follow these steps:
- From the vSphere Client, right-click on the host you want to remove from a cluster.
- Right-click the host to remove and select the Maintenance Mode | Enter Maintenance Mode option, then click OK to proceed. If DRS is enabled, powered-off (you need to enable the option) and running VMs are migrated to other hosts in the cluster.
- When the host enters into Maintenance Mode, the host icon changes. Right-click on the host and select the Move To... option .
- Select the destination (data center, folder, or a different cluster) to move the host to and click OK.
- When the host has moved off the cluster, right-click on the host and select Maintenance Mode | Exit Maintenance Mode.
VMs in the host can now be powered on.
If you want to move a host in a cluster from one vCenter Server to another, you can disconnect the host and move it without putting the host in Maintenance Mode.