Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 585 discussion

Option D: Purchase a Capacity Reservation in the failover Region. Capacity Reservation: Capacity Reservations ensure that you have reserved capacity in a specific region for your instances, regardless of whether you are using On-Demand or Reserved Instances. This is ideal for DR scenarios because it guarantees that the required EC2 capacity will be available when needed.

"Business requirements state that the DR strategy must meet capacity in the failover Region" so only D meets these requirements A. No reservation of capacity B. Saving plans don't guarantee capacity C. Can be possible but it's like an active instance so doesn't really make sense

Purchase a Capacity Reservation in the failover Region: A Capacity Reservation allows you to reserve a specific amount of EC2 instance capacity in a given region without purchasing specific instances. This reserved capacity is dedicated to your account and can be utilized for launching instances when needed. Capacity Reservations offer flexibility, allowing you to launch different instance types and sizes within the reserved capacity. Purchase regional Reserved Instances in the failover Region: Regional Reserved Instances involve paying an upfront fee to reserve a certain number of specific EC2 instances in a particular region. These reserved instances are of a predefined type and size, providing a more traditional reservation model. Regional Reserved Instances are specific to a designated region and ensure that the reserved instances of a particular specification are available when needed.

D Ask is to reserve capacity with RI capacity is not reserved also you can reserve capacity along with RI but only in AZ . https://repost.aws/knowledge-center/ri-reserved-capacity

Capacity Reservations mitigate against the risk of being unable to get On-Demand capacity in case there are capacity constraints. If you have strict capacity requirements, and are running business-critical workloads that require a certain level of long or short-term capacity assurance, create a Capacity Reservation to ensure that you always have access to Amazon EC2 capacity when you need it, for as long as you need it.

Capacity Reservations enable you to reserve capacity for your Amazon EC2 instances in a specific Availability Zone for any duration. This gives you the flexibility to selectively add capacity reservations and still get the Regional RI discounts for that usage. By creating Capacity Reservations, you ensure that you always have access to Amazon EC2 capacity when you need it, for as long as you need it.

Capacity Reservations allocate EC2 capacity in a specific AWS Region for you to launch instances. The capacity is reserved and available to be utilized when needed, meeting the requirement to provide EC2 capacity in the failover region. Other options do not reserve capacity. On-Demand provides flexible capacity but does not reserve capacity upfront. Savings Plans and Reserved Instances provide discounts but do not reserve capacity. Capacity Reservations allow defining instance attributes like instance type, platform, Availability Zone so the reserved capacity matches the production environment.

A regional Reserved Instance does not reserve capacity https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/reserved-instances-scope.html

reserved instances for price discount. need capacity reservation.

The Reserved Instance discount applies to instance usage within the instance family, regardless of size.

D https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-capacity-reservations.html