Creating or deleting mount targets in a VPC

To access an Amazon EFS file system in a VPC, you need mount targets. For an Amazon EFS file system, the following is true:

• You can create one mount target in each Availability Zone.

• If the VPC has multiple subnets in an Availability Zone, you can create a mount target in only one of those subnets. All EC2 instances in the Availability Zone can share the single mount target.

Note

We recommend that you create a mount target in each of the Availability Zones. There are cost considerations for mounting a file system on an EC2 instance in an Availability Zone through a mount target created in another Availability Zone. For more information, see Amazon EFS. In addition, by always using a mount target local to the instance's Availability Zone, you remove a partial failure scenario. If the mount target's zone goes down, you can't access your file system through that mount target.

If you delete a mount target, the operation forcibly breaks any mounts of the file system, which might disrupt instances or applications using those mounts. To avoid application disruption, stop applications and unmount the file system before deleting the mount target. For more information, see Managing mount targets.

Note

Before deleting a mount target, first unmount the file system. For more information, see Unmounting file systems.

You can use a file system only in one VPC at a time. That is, you can create mount targets for the file system in one VPC at a time. If you want to access the file system from another VPC, first delete the mount targets from the current VPC. Then create new mount targets in another VPC.

Using the AWS Management Console, the AWS CLI, and the API, you can create and manage mount targets on file systems. For existing mount targets, you can add and remove security groups, or delete the mount target. For more information, see Managing mount targets.