Entering Maintenance Mode with Workload Balancing Enabled

When Workload Balancing is enabled, if you take a physical host offline for maintenance (that is, suspend a server by entering Maintenance Mode), XenServer automatically migrates the virtual machines running on that host to their optimal servers when available. XenServer migrates them based on Workload Balancing recommendations (performance data, your placement strategy, and performance thresholds).

If an optimal server is not available, the words Click here to suspend the VM appear in the Enter Maintenance Mode dialog box. In this case, Workload Balancing does not recommend a placement because no host has sufficient resources to run this virtual machine. You can either suspend this virtual machine or exit Maintenance Mode and suspend a virtual machine on another host in the same pool. Then, if you reenter the Enter Maintenance Mode dialog box, Workload Balancing might be able to list a host that is a suitable candidate for migration.

Note: When you take a server offline for maintenance and Workload Balancing is enabled, the words “Workload Balancing” appear in the upper-right corner of the Enter Maintenance Mode dialog box.

To enter maintenance mode with Workload Balancing enabled

1. In the Resources pane, select the server and then do one of the following:
   • Right-click and click Enter Maintenance Mode on the shortcut menu.
   • On the Server menu, click Enter Maintenance Mode.
2. Click Enter Maintenance Mode. The virtual machines running on the server are automatically migrated to the optimal host based on Workload Balancing’s performance data, your placement strategy, and performance thresholds.

To take the server out of maintenance mode

1. In the Resources pane, select the server and then do one of the following:
   • Right-click and click Exit Maintenance Mode on the shortcut menu.
   • On the Server menu, click Exit Maintenance Mode.

2. Click Exit Maintenance Mode.

   When you remove a server from maintenance mode, XenServer automatically restores that server’s original virtual machines to that server.