Enabling DRO and reviewing DRO events

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The Dynamic Resource Optimizer (DRO) continuously monitors the usage of the physical hosts and virtual machines in your cloud environment. When a host is found to be over used, the DRO performs a set of actions over time to try to fix the situation. These actions include migrating virtual machines and, for hosts that are members of an Enterprise Pool, activating unused cores. Activating unused cores is only an option for correcting CPU imbalances.

You can customize DRO to perform actions or to simply monitor and recommend actions. Additionally, DRO can be enabled on a host group while certain hosts or virtual machines are excluded from DRO. DRO operations can be scheduled to run during specific times of the day. You must have Administrator authority to change DRO settings.

Overview: Managing DRO on a host group, host, or virtual machine

By default, the DRO is disabled on host groups and is enabled on hosts and virtual machines. However, no optimization occurs unless the DRO is enabled on the host group. You can disable DRO on individual hosts or virtual machines at any time. The following scenarios describe what happens if the DRO is set up in different ways for this environment:

This figure shows how you can include or exclude DRO:
  1. DRO is disabled on the host group: No automated optimization is performed on Host 1, Host 2, or Host 3.
  2. DRO is enabled on the host group but Host 1 is excluded from DRO: DRO can migrate virtual machines between Host 2 and Host 3, but DRO will not migrate virtual machines off of or onto Host 1. Additionally, if Host 1, Host 2, and Host 3 are members of an Enterprise Pool, DRO might use CoD to activate cores on Host 2 or Host 3 if they become overburdened. DRO will not activate cores on Host 1. Likewise, if CoD operations are enabled for DRO, it will not change the CoD allocations for the excluded hosts. However, CoD resources can still be allocated to the remaining hosts if necessary.
  3. DRO is enabled on the host group and enabled on all hosts, but Virtual Machine A is excluded from DRO: Optimization is performed on Host 1, Host 2, and Host 3, but Virtual Machine A is never migrated. All other virtual machines could migrate to any host in the host group.
  4. The DRO is enabled on the host group and no host or virtual machine is excluded from DRO: Optimization is performed on all of the hosts, and all of the virtual machines could migrate to any other host within the host group.

Enable DRO on a host group

  1. Navigate to Hosts > Groups and click the host group on which you want to enable DRO.
  2. Select Configure DRO, fill out the settings, and click Save.
    Note: Ensure that Run interval x Stabilization is at least 5 minutes. For example, 5 minutes x 2 times = 10 minutes. This is necessary because virtual machine utilization data is polled every five minutes and the DRO needs time to stabilize after an optimization cycle to ensure that it makes reliable decisions.

Exclude a host or virtual machine from DRO activity

By default, if the DRO is enabled on a host group, optimization actions apply to every host in the host group and every virtual machine on each included host. However, there might be some hosts or virtual machines that you want to exclude from DRO operations. Follow these steps to exclude a host or virtual machine from DRO operations. You can change this setting at any time.

  1. Open the Hosts page or the Virtual Machines page.
  2. Double-click the host or virtual machine that you want to work with, then click the edit link next to the Excluded from DRO property value.
  3. In the dialog that appears, select the check box.

Review the DRO events

To review DRO events, click DRO Events in the top menu bar. The DRO events tab displays events only for hosts that are a member of a host group in which DRO is enabled. The following DRO events are displayed:
  • Operations that were advised or performed by DRO
  • When a host exceeds its utilization threshold
  • When a utilization threshold for a host is satisfied
To enable email notifications for DRO events, go to Configuration > Email Templates and enable DRO Event Notifications. These notifications are sent only for hosts that are members of a host group with DRO enabled. Make sure that the email server is correctly configured for the project to receive emails. For details, see . Email notifications for DRO events are sent under following conditions:
  • Operations that were advised or performed by DRO.
  • When a host exceeds its utilization threshold.
  • When a utilization threshold for a host is satisfied.

DRO Schedule

In PowerVC, you can enable the DRO by schedule at the host group level. Select Always enable DRO to keep DRO enabled at all times. Select Enable DRO during specific times for DRO to be enabled during specific time frames. For example, Tuesdays at 10:00 PM through Wednesdays at 6:00 AM, Fridays at 8:00 PM through Mondays at 5:00 AM, and so on. Because the schedule is checked once per minute, there might be a 1 minute delay for the DRO to enter or exit a scheduled time frame.