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VMware Cloud on AWS

Enhancement to Elastic DRS Rapid Scale-Out policy for VMware Cloud on AWS

The new Rapid Scale-Out policy for VMware Cloud on AWS is ideal for events like disaster recovery and bulk workload migration – enabling you to add up to 12 hosts in parallel at one time for lightning fast scalability. Rapid Scale-Out is just one option within the Elastic DRS feature in VMware Cloud on AWS.

Elastic DRS (EDRS) is a very useful feature included with VMware Cloud on AWS for last couple of years. With the existing EDRS policies for storage, performance, and cost, the scale-out of a cluster only occurs after resource demands remain high for a certain period of time. Once the scale-out is triggered, hosts are added conservatively, in a serial fashion, one at a time.

Today, I’m happy to announce that an enhancement to the Rapid Scale-Out is now available. This enhancement enables cluster scale out faster by adding 12 hosts in parallel compared to 4 hosts that was previously supported

Rapid Scale-Out

EDRS Rapid Scale-Out is configured to react faster and to add hosts in parallel, up to Twelve (12) at a time, to allow a cluster to scale-out more quickly during an event. Some primary use cases that can benefit from this new policy are disaster recovery events, significant VDI DR and burst use cases, or even bulk workload migration/power-on events. The Rapid Scale-Out maximum resources thresholds are the same as the EDRS Performance Policy thresholds which is 80%, but the minimum thresholds are set to 0%. This allows for a scale-out task to kick off quicker but also means we will not automatically scale-in; scale-in will be a manual process driven by the customer. As an example, with the new rapid scale out policy for elastic DRS, 12 hosts could be deployed in parallel in 40 mins, compared to 130 mins if hosts deployed serially. For more details on the Elastic DRS Rapid Scale out policy, please refer to this documentation.

Enabling the Policy

To enable EDRS Rapid Scale-Out, edit the EDRS settings of your cluster as shown below, and choose the new policy.


You can also enable this via the edrs-policy API. To learn more, please check out this article on managing EDRS policies via RESTful APIs


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