AWS Certified Solutions Architect – Professional SAP-C01 – Question380

You have custom Network File System (NFS) client settings for your Amazon Elastic File System (EFS). It takes up to three seconds for an Amazon Elastic Compute Cloud (EC2) instance to see a write operation performed on a file system from another Amazon EC2 instance.
Which of the following actions should you take to solve the custom NFS settings from causing delays in the write operation?

A.
Unmount and remount the file system with the noac option to disable attribute caching.
B. Reduce the number of active users that have files open simultaneously on the instances.
C. Verify that the IP address of the specified mount target is valid.
D. Run the write operation from a different user ID on the same Amazon EC2 instance.

Correct Answer: A

Explanation:

Explanation: When you set up custom NFS client settings, it takes up to three seconds for an Amazon EC2 instance to see a write operation being performed on a file system from another Amazon EC2 instance. To solve this issue, you must unmount and remount your file system with the noac option to disable attribute caching if the NFS client on the Amazon EC2 instance that is reading the data has attribute caching activated. Attribute cache can also be cleared on demand by using a programming language that is compatible with the NFS procedures. To do this, you must send an ACCESS procedure request immediately before a read request.
Reference:
http://docs.aws.amazon.com/efs/latest/ug/troubleshooting.html#custo…