Sign in

v1

latestOpenAPI 3.0.0Apache 2.0 License2026-07-1431160173.1 KB

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.

post/2015-02-01/file-systems

Request body

CreationTokenstring required

A string of up to 64 ASCII characters. Amazon EFS uses this to ensure idempotent creation.

PerformanceMode'generalPurpose' | 'maxIO'
<p>The performance mode of the file system. We recommend <code>generalPurpose</code> performance mode for all file systems. File systems using the <code>maxIO</code> performance mode can scale to higher levels of aggregate throughput and operations per second with a tradeoff of slightly higher latencies for most file operations. The performance mode can't be changed after the file system has been created. The <code>maxIO</code> mode is not supported on One Zone file systems.</p> <important> <p>Due to the higher per-operation latencies with Max I/O, we recommend using General Purpose performance mode for all file systems.</p> </important> <p>Default is <code>generalPurpose</code>.</p>
Encryptedboolean

A Boolean value that, if true, creates an encrypted file system. When creating an encrypted file system, you have the option of specifying an existing Key Management Service key (KMS key). If you don't specify a KMS key, then the default KMS key for Amazon EFS, <code>/aws/elasticfilesystem</code>, is used to protect the encrypted file system.

KmsKeyIdstring
<p>The ID of the KMS key that you want to use to protect the encrypted file system. This parameter is required only if you want to use a non-default KMS key. If this parameter is not specified, the default KMS key for Amazon EFS is used. You can specify a KMS key ID using the following formats:</p> <ul> <li> <p>Key ID - A unique identifier of the key, for example <code>1234abcd-12ab-34cd-56ef-1234567890ab</code>.</p> </li> <li> <p>ARN - An Amazon Resource Name (ARN) for the key, for example <code>arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code>.</p> </li> <li> <p>Key alias - A previously created display name for a key, for example <code>alias/projectKey1</code>.</p> </li> <li> <p>Key alias ARN - An ARN for a key alias, for example <code>arn:aws:kms:us-west-2:444455556666:alias/projectKey1</code>.</p> </li> </ul> <p>If you use <code>KmsKeyId</code>, you must set the <a>CreateFileSystemRequest$Encrypted</a> parameter to true.</p> <important> <p>EFS accepts only symmetric KMS keys. You cannot use asymmetric KMS keys with Amazon EFS file systems.</p> </important>
ThroughputMode'bursting' | 'provisioned' | 'elastic'
<p>Specifies the throughput mode for the file system. The mode can be <code>bursting</code>, <code>provisioned</code>, or <code>elastic</code>. If you set <code>ThroughputMode</code> to <code>provisioned</code>, you must also set a value for <code>ProvisionedThroughputInMibps</code>. After you create the file system, you can decrease your file system's Provisioned throughput or change between the throughput modes, with certain time restrictions. For more information, see <a href="https://docs.aws.amazon.com/efs/latest/ug/performance.html#provisioned-throughput">Specifying throughput with provisioned mode</a> in the <i>Amazon EFS User Guide</i>. </p> <p>Default is <code>bursting</code>.</p>
ProvisionedThroughputInMibpsnumber double

The throughput, measured in mebibytes per second (MiBps), that you want to provision for a file system that you're creating. Required if <code>ThroughputMode</code> is set to <code>provisioned</code>. Valid values are 1-3414 MiBps, with the upper limit depending on Region. To increase this limit, contact Amazon Web Services Support. For more information, see <a href="https://docs.aws.amazon.com/efs/latest/ug/limits.html#soft-limits">Amazon EFS quotas that you can increase</a> in the <i>Amazon EFS User Guide</i>.

AvailabilityZoneNamestring
<p>For One Zone file systems, specify the Amazon Web Services Availability Zone in which to create the file system. Use the format <code>us-east-1a</code> to specify the Availability Zone. For more information about One Zone file systems, see <a href="https://docs.aws.amazon.com/efs/latest/ug/availability-durability.html#file-system-type">EFS file system types</a> in the <i>Amazon EFS User Guide</i>.</p> <note> <p>One Zone file systems are not available in all Availability Zones in Amazon Web Services Regions where Amazon EFS is available.</p> </note>
Backupboolean
<p>Specifies whether automatic backups are enabled on the file system that you are creating. Set the value to <code>true</code> to enable automatic backups. If you are creating a One Zone file system, automatic backups are enabled by default. For more information, see <a href="https://docs.aws.amazon.com/efs/latest/ug/awsbackup.html#automatic-backups">Automatic backups</a> in the <i>Amazon EFS User Guide</i>.</p> <p>Default is <code>false</code>. However, if you specify an <code>AvailabilityZoneName</code>, the default is <code>true</code>.</p> <note> <p>Backup is not available in all Amazon Web Services Regions where Amazon EFS is available.</p> </note>

Response

Success

OwnerIdstring required

The Amazon Web Services account that created the file system.

CreationTokenstring required

The opaque string specified in the request.

FileSystemIdstring required

The ID of the file system, assigned by Amazon EFS.

FileSystemArnstring

The Amazon Resource Name (ARN) for the EFS file system, in the format <code>arn:aws:elasticfilesystem:<i>region</i>:<i>account-id</i>:file-system/<i>file-system-id</i> </code>. Example with sample data: <code>arn:aws:elasticfilesystem:us-west-2:1111333322228888:file-system/fs-01234567</code>

CreationTimestring date-time required

The time that the file system was created, in seconds (since 1970-01-01T00:00:00Z).

LifeCycleState'creating' | 'available' | 'updating' | 'deleting' | 'deleted' | 'error' required

The lifecycle phase of the file system.

Namestring

You can add tags to a file system, including a <code>Name</code> tag. For more information, see <a>CreateFileSystem</a>. If the file system has a <code>Name</code> tag, Amazon EFS returns the value in this field.

NumberOfMountTargetsinteger required

The current number of mount targets that the file system has. For more information, see <a>CreateMountTarget</a>.

PerformanceMode'generalPurpose' | 'maxIO' required

The performance mode of the file system.

Encryptedboolean

A Boolean value that, if true, indicates that the file system is encrypted.

KmsKeyIdstring

The ID of an KMS key used to protect the encrypted file system.

ThroughputMode'bursting' | 'provisioned' | 'elastic'

Displays the file system's throughput mode. For more information, see <a href="https://docs.aws.amazon.com/efs/latest/ug/performance.html#throughput-modes">Throughput modes</a> in the <i>Amazon EFS User Guide</i>.

ProvisionedThroughputInMibpsnumber double

The amount of provisioned throughput, measured in MiBps, for the file system. Valid for file systems using <code>ThroughputMode</code> set to <code>provisioned</code>.

AvailabilityZoneNamestring

Describes the Amazon Web Services Availability Zone in which the file system is located, and is valid only for One Zone file systems. For more information, see <a href="https://docs.aws.amazon.com/efs/latest/ug/storage-classes.html">Using EFS storage classes</a> in the <i>Amazon EFS User Guide</i>.

AvailabilityZoneIdstring

The unique and consistent identifier of the Availability Zone in which the file system is located, and is valid only for One Zone file systems. For example, <code>use1-az1</code> is an Availability Zone ID for the us-east-1 Amazon Web Services Region, and it has the same location in every Amazon Web Services account.