A solutions architect has launched multiple Amazon EC2 instances in a placement group within a single Availability Zone. Because of additional load on the system, the solutions architect attempts to add new instances to the placement group. However, the solutions architect receives an insufficient capacity error.
What should the solutions architect do to troubleshoot this issue?
When you receive an insufficient capacity error while trying to add new instances to an existing placement group, the recommended action is to stop and start all the instances in the placement group. This allows the instances to be migrated to hardware that has sufficient capacity for the requested instances.
Correct B.
The correct answer is B: If you receive a capacity error when launching an instance in a placement group that already has running instances, stop and start all of the instances in the placement group, and try the launch again. C - is wrong "You can't merge placement groups." https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html
If you try to add more instances to the placement group later, or if you try to launch more than one instance type in the placement group, you increase your chances of getting an insufficient capacity error. If you stop an instance in a placement group and then start it again, it still runs in the placement group. However, the start fails if there isn't enough capacity for the instance. If you receive a capacity error when launching an instance in a placement group that already has running instances, stop and start all of the instances in the placement group, and try the launch again. Starting the instances may migrate them to hardware that has capacity for all of the requested instances. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html#placement-groups-cluster
C is wrong. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html General rules and limitations > You can't merge placement groups.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html#placement-groups-cluster
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html#placement-groups-cluster