Your team is developing a new big data analysis application and requires you to create a file system in Amazon EFS with the General Purpose performance mode. During the test, it has been found that the file system has some performance issues. The PercentIOLimit CloudWatch metric of the file system is at 100 percent most of the time. Which of the following actions should you take to overcome this issue?

Answer options:

A.Create a read replica of the file system to share the read traffic.
B.Configure the Provisioned Throughput to be 200 MiB/s.
C.Enlarge the burst credits of the file system.
D.Create the EFS file system with the Max I/O performance mode.

Correct Answer: D
Option A is incorrect because unlike RDS, the Amazon EFS file system does not have read replicas.
Option B is incorrect because users can configure the performance mode and the throughput mode in EFS. The performance mode is General Purpose, but the throughput mode is unknown. But changing the throughput mode cannot enhance the performance. This option is not accurate. https://docs.aws.amazon.com/efs/latest/ug/performance.html
Option C is incorrect because the question does not mention whether the EFS file system has a burst credit issue and users cannot manually modify the credit of the file system.
Option D is CORRECT because the PercentIOLimit metric checks how close the file system reaches the I/O limit. If the metric is at 100 percent, the Max I/O performance mode should be considered. When creating an EFS file system, users can choose the performance mode to be General Purpose or Max I/O as follows:
References:
https://docs.aws.amazon.com/efs/latest/ug/performance.html,
https://docs.aws.amazon.com/efs/latest/ug/efs-metrics.html