createFileSystem

Creates a new, empty file system. The operation requires a creation token in the request that Amazon EFS uses to ensure idempotent creation (calling the operation with same creation token has no effect). If a file system does not currently exist that is owned by the caller's Amazon Web Services account with the specified creation token, this operation does the following:

• Creates a new, empty file system. The file system will have an Amazon EFS assigned ID, and an initial lifecycle state creating.

• Returns with the description of the created file system.

Otherwise, this operation returns a FileSystemAlreadyExists error with the ID of the existing file system.

For basic use cases, you can use a randomly generated UUID for the creation token.

The idempotent operation allows you to retry a CreateFileSystem call without risk of creating an extra file system. This can happen when an initial call fails in a way that leaves it uncertain whether or not a file system was actually created. An example might be that a transport level timeout occurred or your connection was reset. As long as you use the same creation token, if the initial call had succeeded in creating a file system, the client can learn of its existence from the FileSystemAlreadyExists error.

For more information, see Creating a file system in the Amazon EFS User Guide.

The CreateFileSystem call returns while the file system's lifecycle state is still creating. You can check the file system creation status by calling the DescribeFileSystems operation, which among other things returns the file system state.

This operation accepts an optional PerformanceMode parameter that you choose for your file system. We recommend generalPurpose``PerformanceMode for all file systems. The maxIO mode is a previous generation performance type that is designed for highly parallelized workloads that can tolerate higher latencies than the generalPurpose mode. MaxIO mode is not supported for One Zone file systems or file systems that use Elastic throughput.

The PerformanceMode can't be changed after the file system has been created. For more information, see Amazon EFS performance modes.

You can set the throughput mode for the file system using the ThroughputMode parameter.

After the file system is fully created, Amazon EFS sets its lifecycle state to available, at which point you can create one or more mount targets for the file system in your VPC. For more information, see CreateMountTarget. You mount your Amazon EFS file system on an EC2 instances in your VPC by using the mount target. For more information, see Amazon EFS: How it Works.

This operation requires permissions for the elasticfilesystem:CreateFileSystem action.

File systems can be tagged on creation. If tags are specified in the creation action, IAM performs additional authorization on the elasticfilesystem:TagResource action to verify if users have permissions to create tags. Therefore, you must grant explicit permissions to use the elasticfilesystem:TagResource action. For more information, see Granting permissions to tag resources during creation.