What Is Maintenance Mode in Vmware?

What Is Maintenance Mode in Vmware?

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You put the host in maintenance mode when you need to service it, for example, to install more memory. The host enters or exits the maintenance mode only at the user’s request. Virtual machines running on a host that joins maintenance mode need to migrate to another host, manually or automatically, with DRS.

Administrators exclude their hosts from service from time to time. After closing single node maintenance, the resources of the vSAN cluster need to be redistributed, and this is where VMware maintenance mode comes into play.

VMware vSphere maintenance mode

When DRS maintenance mode is enabled, DRS is used to evacuate all virtual machines without interruption from one host to another. It is beneficial for maintaining, updating the ESXi host, installing additional memory, firmware upgrades, etc.

A cluster must be created to use the maintenance mode in the vSphere architecture and DRS enabled. We are able to add the desired hosts to the collection when the kit is designed with DRS included. After adding the hosts to the group, select the host to switch to maintenance mode.

Once the administrator confirms the activation of the maintenance mode, the virtual machines from this host will be moved using vMotion to other hosts on the same cluster without any interruption.

How to enable virtualization in vSphere

  • Make sure the virtual machine is off.
  • Open the properties page of that virtual machine.
  • Select the Processors and Memory page.
  • Select the check box next to Enable hypervisor applications in this virtual machine.
  • Restart the server.

ESXi maintenance mode

ESXi maintenance mode is where patches and updates can be installed or hardware upgrades planned, such as adding more RAM or multiple internal hard drives.

You may need to service your host to install the new firmware on the storage controller, motherboard, etc. It would be soundest permanently to ensure that the virtual machines are migrating from the host and that the host is in the preferred mode before restarting or shutting down the host operating any method.

You can also continue the host agents on the ESXi host console. This often reconnects them to vCenter. These are individual ESXi servers used by our developers.

Each developer has their ESXi server to host their releases, etc., so they have full access to the host and guests they create.

Configure Maintenance Mode for New Virtual Machines

Virtual Host Manager automatically models the virtual machines that vCenter manages and tries to address all detected models. However, some virtual machines are not ready to operate when modeled initially – for example, generating a virtual machine shutdown alarm when it detects virtual machines being turned off.

To prevent unwanted alarms on newer models, you can select virtual machine models that will be immediately put into maintenance mode. Later, you can manually disable the maintenance mode when you are ready to operate these devices.

In the dawn of the outcomes obtained from the laboratory mouse model and the results obtained from field studies, a maintenance host can be defined as an animal qualified of acting as a natural source of leptospiral condition for its species.

Putting a host in maintenance mode

We are able to activate maintenance mode via vCenter. You can also enter this mode for a standalone host in the web console. There’s a way to enter the method from an SSH session for CLI-minded users. Here are three commands that may come in handy:

  1. esxcli system maintenanceMode – to inform whether maintenance mode is enabled
  2. esxcli system maintenanceMode accurate set
  3. esxcli system maintenanceMode false set


If a maintenance mode got stuck at 2%

The ESX or ESXi server will not end up in maintenance mode until running a running VM. Maintenance mode can get stuck with a 2% upgrade when there are still active VMs running on that ESX host.

To exit maintenance mode, running virtual machines on ESXi hosts can manually migrate if a failover capacity is overwhelmed. More running virtual machines are enough resources to host into maintenance mode.

If you have configured HA, it should automatically shut down the VMs of another ESX host with sufficient resources. If you also use DRS, it will do some load balancing and work out all the affinity rules.

What can prevent VMs from automatically moving to another host is:

  • CD is still attached to the VM – If so, remove it.
  • The vNIC virtual machine is only attached to an internal network, or vSwitch is not available on another ESX server – Check the spelling of vSwitches and what type of network the VM is connected to.
  • VMtools currently installed on the Virtual Machine – Wait for the installation to complete or cancel.
  • The virtual machine is stored in a data store locally on that ESX host – the VM should be in a centralized data store (SAN, etc.) available to another ESX host.

When the ESXi host is down …

If the ESXi host is turned off, HA will continue to restart the included VMs before vCenter becomes unavailable. All VMs connected to a distributed switch (vDS) will continue to have access to the network, but you will not be able to change the vDS configuration.


All virtual machines running the host by entering maintenance mode must be turned off or migrated to other hosts. Once the host joins the maintenance mode, no VM can be deployed or enabled on the host. To enter the

maintenance mode option, the admission control can migrate virtual machines to ESXi maintenance mode.

The hosts can also be put in standby mode. The maintenance mode feature allows the host or server to be offline without interrupting the service. Maintenance mode works with dynamic routing and automatic scaling functions to prevent client requests from being disrupted by routing client traffic around the server in maintenance mode on another server.

Some live streaming installations and updates require the cluster host to be put into maintenance mode. All virtual machines running the host that enters maintenance mode must be turned off or migrated to other hosts.

Once the host joins the maintenance mode, no VM can be deployed or enabled on the host. Host entering maintenance mode will take care of all the virtual machines on the VMware ESXi host.