ESXi host updates might require that the host enters maintenance mode before they can be applied. Update Manager puts the ESXi hosts in maintenance mode before applying these updates. You can configure how Update Manager responds if the host fails to enter maintenance mode.

For hosts in a container different from a cluster or for individual hosts, migration of the virtual machines with vMotion cannot be performed. If vCenter Server cannot migrate the virtual machines to another host, you can configure how Update Manager responds.

Hosts that are part of a Virtual SAN cluster can enter maintenance mode only one at a time. This is specificity of the Virtual SAN clusters.

If a host is a member of a Virtual SAN cluster, and any virtual machine on the host uses a VM storage policy with a setting for "Number of failures to tolerate=0", the host might experience unusual delays when entering maintenance mode. The delay occurs because Virtual SAN has to migrate the virtual machine data from one disk to another in the Virtual SAN datastore cluster. Delays might take up to hours. You can workaround this by setting the "Number of failures to tolerate=1" for the VM storage policy, which results in creating two copies of the virtual machine files in the Virtual SAN datastore.


Required privileges: VMware vSphere Update Manager.Configure


  1. Use the vSphere Client or the vSphere Web Client to connect to a vCenter Server system with which Update Manager is registered.
  2. Depending on the client you use to connect to vCenter Server perform the following steps.
    Client Steps
    vSphere Web Client
    1. On the Settings tab, under Manage, click Host/Cluster Settings.

    Click Edit.

    vSphere Client
    1. On the Configuration tab, under Settings, click ESXi Host/Cluster Settings.
  3. Under Maintenance Mode Settings, select an option from the VM Power state drop-down menu to determine the change of the power state of the virtual machines and appliances that are running on the host to be remediated.
    Option Description
    Power Off virtual machines Powers off all virtual machines and virtual appliances before remediation.
    Suspend virtual machines Suspends all running virtual machines and virtual appliances before remediation.
    Do Not Change VM Power State Leaves virtual machines and virtual appliances in their current power state. This is the default setting.
  4. (Optional) Select Retry entering maintenance mode in case of failure, specify the retry delay, and the number of retries.
    If a host fails to enter maintenance mode before remediation, Update Manager waits for the retry delay period and retries putting the host into maintenance mode as many times as you indicate in Number of retries field.
  5. (Optional) Select Temporarily disable any removable media devices that might prevent a host from entering maintenance mode.
    Update Manager does not remediate hosts on which virtual machines have connected CD/DVD or floppy drives. All removable media drives that are connected to the virtual machines on a host might prevent the host from entering maintenance mode and interrupt remediation.

    After remediation, Update Manager reconnects the removable media devices if they are still available.

  6. Click Apply.


These settings become the default failure response settings. You can specify different settings when you configure individual remediation tasks.