Using vSphere HA cluster options when periodic network/host maintenance is required

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article provides information on steps to take when conducting periodic maintenance of networking or ESXi/ESX hosts when using vSphere HA.

Environment

VMware vCenter Server 5.1.x
VMware vCenter Server 5.0.x
VMware ESX 4.0.x
VMware vSphere ESXi 5.1
VMware vSphere ESXi 5.0
VMware vSphere ESXi 5.5
VMware ESXi 4.1.x Installable
VMware ESXi 4.0.x Installable
VMware vCenter Server 5.5.x
VMware vCenter Server 4.1.x
VMware vCenter Server 4.0.x
VMware ESX 4.1.x

Resolution

If you conduct a network/host maintenance without first disabling Host Monitoring, you may see that the virtual machines either failover or are restarted on other hosts.

To disable Host Monitoring:

1. In the vSphere Client, right-click the cluster and click Edit Settings.
2. Click vSphere HA and deselect Enable Host Monitoring.
3. Click OK.
4. After maintenance is complete, re-enable Host Monitoring.

If you need to perform service on your hosts, for example to install more memory, you must enter Maintenance Mode.

To enter Maintenance Mode:

1. In the vSphere Client inventory, right-click a host and click Enter Maintenance Mode.
   
   
   • If the host is part of a partially automated or manual DRS cluster, a list of migration recommendations for virtual machines running on the host appears.
   • If the host is part of an automated DRS cluster, virtual machines are migrated to different hosts when the host enters maintenance mode.
     
     
2. If applicable, click Apply Recommendations.
   
   The host is in maintenance mode until you select Exit Maintenance Mode.
   
   Note: If vCenter Server is a virtual machine on a host you wish to place into Maintenance Mode, you may have to manually migrate prior to entering into Maintenance Mode. For more information, see Update Manager fails to remediate a host with the error: The host <hostname> has a VM <vmname> with VMware vCenter Update Manager or VMware vCenter installed (1017979).
   

Additional Information

• For information regarding vSphere HA Clusters, see the vSphere Availability Guide for your version.
• For HA deployment best practices in vSphere vCenter 4.1, see VMware High Availability (VMware HA): Deployment Best Practices.
• For HA deployment best practices in vSphere vCenter 5.0, see vSphere High Availability Deployment Best Practices.

Update Manager fails to remediate a host with the error: The host <hostname> has a VM <vmname> with VMware vCenter Update Manager or VMware vCenter installed