itsexe
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Enthusiast

What deos acually maintenance mode do?

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Hi Can any one please explain what does the maintenance mode do? what is its puprose its still not clear to me.

Regards,

Khurram Shahzad

Regards, Khurram Shahzad
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weinstein5
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Having an ESX Server enter maintenance mode will prevent users from starting VMs on that host or vmotioning to that host - very important if you have distributed administrators and especially important if the host is part of an DRS/HA cluster - it will prevent DRS from automatically starting or vmotioning vms to that host and giving you method to bring down your esx server without causing an HA event -

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weinstein5
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Immortal

Having an ESX Server enter maintenance mode will prevent users from starting VMs on that host or vmotioning to that host - very important if you have distributed administrators and especially important if the host is part of an DRS/HA cluster - it will prevent DRS from automatically starting or vmotioning vms to that host and giving you method to bring down your esx server without causing an HA event -

If you find this or any other answer useful please consider awarding points by marking the answer correct or helpful

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itsexe
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Hi Weinstein,

Thanks for the answer. Is there any document describing the maintenance mode in more details.

Still thanks a lot.

Regards,

Khurram Shahzad

Regards, Khurram Shahzad
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weinstein5
Immortal
Immortal

This is from the Resource Management Guide:http: //www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_resource_mgmt.pdf

Maintenance Mode

Standalone hosts and hosts within a cluster support a maintenance mode, which restricts the virtual machine operations on the host to allow you to shut down running virtual machines in preparation for host shut down. Only ESX Server 3.0 and later supports maintenance mode for standalone hosts.

A host enters or leaves maintenance mode only as the result of a user request. If the host is in a cluster, when it enters maintenance mode the user is given the option to evacuate powered-off virtual machines. If this option is selected, each powered-off virtual machine is migrated to another host, unless there is no compatible host available for the virtual machine in the cluster. While in maintenance mode, the host does not allow you to deploy or power on a virtual machine. Virtual machines that are running on a host entering maintenance mode need to be either migrated to another host or shut down (either manually or automatically by DRS).

Note If DRS can make no migration recommendations for a virtual machine, an event is generated (check the virtual machine’s Tasks & Events tab). The virtual machine must be migrated manually or powered off before the host can enter maintenance mode.

When no more running virtual machines are on the host, the host’s icon changes to include under maintenance and the host’s Summary panel indicates the new state.

The default automation mode of a virtual machine determines its behavior when the host (in a DRS cluster) it is running on enters maintenance mode:

Any fully automated virtual machine is migrated automatically.

Note If no appropriate host is available, DRS displays information on the Tasks & Events tab.

For a partially automated or manual virtual machine, a recommendation for further user action is generated and displayed.

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