AWS Certified SysOps Administrator – Associate — Question 333

A company has a cluster of Linux Amazon EC2 Spot Instances that read many files from and write many files to attached Amazon Elastic Block Store (Amazon EBS) volumes. The EC2 instances are frequently started and stopped. As part of the process when an EC2 instance starts, an EBS volume is restored from a snapshot.

EBS volumes that are restored from snapshots are experiencing initial performance that is lower than expected. The company's workload needs almost all the provisioned IOPS on the attached EBS volumes. The EC2 instances are unable to support the workload when the performance of the EBS volumes is too low. A SysOps administrator must implement a solution to ensure that the EBS volumes provide the expected performance when they are restored from snapshots.

Which solution will meet these requirements?

Answer options

• A. Configure fast snapshot restore (FSR) on the snapshots that are used.
• B. Restore each snapshot onto an unencrypted EBS volume. Encrypt the EBS volume when the performance stabilizes.
• C. Format the EBS volumes as XFS file systems before restoring the snapshots.
• D. Increase the Linux read-ahead buffer to 1 MiB.

Correct answer: A

Explanation

Amazon EBS Fast Snapshot Restore (FSR) eliminates the latency associated with block initialization (pre-warming) when restoring volumes from snapshots, allowing them to instantly deliver full provisioned performance. Other options, such as changing encryption states, formatting to XFS, or modifying Linux read-ahead buffers, do not resolve the first-write penalty of uninitialized blocks. Thus, enabling FSR on the source snapshots is the correct solution to meet the performance demands.