SAA-C03 Practice Question 92: Encrypt Existing EBS Volume
AWS Certified Solutions Architect – Associate (SAA-C03) · Test 10 · question 2 of 10
A compliance review finds that a production EC2 instance has an unencrypted 1 TiB EBS data volume. Policy now requires all data volumes to be encrypted with a customer managed KMS key. The application can tolerate a short maintenance window but its data must be preserved.
Which approach meets the requirement?
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Answer:
The encryption state of an EBS volume is fixed when the volume is created. An unencrypted volume cannot be encrypted in place, but an unencrypted snapshot can be copied with encryption turned on and a KMS key chosen, and a new volume created from that copy is encrypted with the key. Stopping the instance, detaching the old volume, and attaching the new one during the maintenance window completes the change with all data preserved.
Option A is not possible. Elastic Volumes lets you change the size, type, IOPS and throughput of a volume, but not its encryption status.
Option B does not touch existing volumes. Encryption by default applies only to volumes and snapshot copies created after it is enabled, so this would prevent the problem from recurring but would not fix this volume.
Option D misreads how KMS works. A key policy controls who can use the key; it is not attached to a volume, and EBS never encrypts an unencrypted volume block by block as it is written.
Reference: Amazon EBS encryption