Amazon Elastic File System
User Guide

Amazon EFS Limits

Following, you can find out about limitations when working with Amazon EFS.

Amazon EFS Limits That You Can Increase

You can increase the following Amazon EFS limit by contacting AWS Support.

Resource Default Limit
Number of file systems for each customer account in an AWS Region 1,000

You can work with the following throughput limits by using the throughput mode that you choose for your file system, Bursting or Provisioned. For more information on these different modes, see Amazon EFS Performance.

Resource Default Limit
Total bursting throughput for all connected clients

US East (Ohio) Region – 3 GB/s

US East (N. Virginia) Region – 3 GB/s

US West (N. California) Region – 1 GB/s

US West (Oregon) Region – 3 GB/s

Asia Pacific (Mumbai) – 1 GB/s

Asia Pacific (Seoul) – 1 GB/s

Asia Pacific (Singapore) – 1 GB/s

Asia Pacific (Tokyo) – 1 GB/s

Canada (Central) – 1 GB/s

EU (Frankfurt) Region – 1 GB/s

EU (Ireland) Region – 3 GB/s

EU (London) Region – 1 GB/s

EU (Paris) Region – 1 GB/s

Asia Pacific (Sydney) Region – 3 GB/s

Total provisioned throughput for all connected clients

All AWS Regions – 1 GB/s

You can take the following steps to request an increase for these limits. These increases are not granted immediately, so it might take a couple of days for your increase to become effective.

To request a limit increase

  1. Open the AWS Support Center page, sign in, if necessary, and then choose Create Case.

  2. Under Regarding, choose Service Limit Increase.

  3. Under Limit Type, choose the type of limit to increase, fill in the necessary fields in the form, and then choose your preferred method of contact.

Resource Limits

Following are the limits on Amazon EFS resources for each customer account in an AWS Region.

Resource Limit
Number of mount targets for each file system in an Availability Zone 1
Number of mount targets for each VPC 400
Number of security groups for each mount target 5
Number of tags for each file system 50
Number of VPCs for each file system 1


Clients can also connect to mount targets in another account or VPC. For more information, see Mounting EFS File Systems from Another Account or VPC.

Limits for NFS Clients

The following limits for NFS clients apply, assuming a Linux NFSv4.1 client:

  • The maximum throughput you can drive for each NFS client is 250 MB/s.

  • Up to 128 active user accounts for each client can have files open at the same time. Each user account represents one local user logged in to the instance. A user account that is logged in multiple times counts as one active user.

  • Up to 32,768 files open at the same time on the instance. Listing directory contents does not count as opening a file.

  • Each unique mount on the client can acquire up to a total of 8,192 locks across a maximum of 256 unique file/process pairs. For example, a single process can acquire one or more locks on 256 separate files, or 8 processes can each acquire one or more locks on 32 files.

  • When connecting to EFS, NFS clients located on-premises or in another AWS Region can observe lower throughput than when connecting to EFS from the same AWS Region due to increased network latency. Network latency of 1 ms or less is required to achieve maximum per-client throughput. Use the AWS DataSync data migration service when migrating large data sets from on-premises servers to Amazon EFS.

  • Using Amazon EFS with Microsoft Windows is not supported.

Limits for Amazon EFS File Systems

The following are limits specific to the Amazon EFS file systems:

  • Maximum name length: 255 bytes.

  • Maximum symbolic link (symlink) length: 4080 bytes.

  • Maximum number of hard links to a file: 177.

  • Maximum size of a single file: 52,673,613,135,872 bytes (47.9 TiB).

  • Maximum directory depth: 1000 levels deep.

  • Any one particular file can have up to 512 locks across all instances connected and users accessing the file.

  • In General Purpose mode, there is a limit of 7000 file system operations per second. This operations limit is calculated for all clients connected to a single file system.

Unsupported NFSv4 Features

Although Amazon Elastic File System does not support NFSv2, or NFSv3, Amazon EFS supports both NFSv4.1 and NFSv4.0, except for the following features:

  • pNFS

  • Client delegation or callbacks of any type

    • Operation OPEN always returns OPEN_DELEGATE_NONE as the delegation type.

    • The operation OPEN returns NFSERR_NOTSUPP for the CLAIM_DELEGATE_CUR and CLAIM_DELEGATE_PREV claim types.

  • Mandatory locking

    All locks in Amazon EFS are advisory, which means that READ and WRITE operations do not check for conflicting locks before the operation is executed.

  • Deny share

    NFS supports the concept of a share deny, primarily used by Windows clients for users to deny others access to a particular file that has been opened. Amazon EFS does not support this, and returns the NFS error NFS4ERR_NOTSUPP for any OPEN commands specifying a share deny value other than OPEN4_SHARE_DENY_NONE. Linux NFS clients do not use anything other than OPEN4_SHARE_DENY_NONE.

  • Access control lists (ACL)

  • Amazon EFS does not update the time_access attribute on file reads. Amazon EFS updates time_access in the following events:

    • When a file is created (an inode is created).

    • When an NFS client makes an explicit setattr call.

    • On a write to the inode caused by, for example, file size changes or file metadata changes.

    • Any inode attribute is updated.

  • Namespaces

  • Persistent reply cache

  • Kerberos based security

  • NFSv4.1 data retention

  • SetUID on directories

  • Unsupported file types when using the CREATE operation: Block devices (NF4BLK), character devices (NF4CHR), attribute directory (NF4ATTRDIR), and named attribute (NF4NAMEDATTR).


    An attempt to set these attributes results in an NFS4ERR_ATTRNOTSUPP error that is sent back to the client.

Additional Considerations

In addition, note the following:

  • For a list of AWS Regions where you can create Amazon EFS file systems, see the AWS General Reference.

  • You mount your file system from EC2 instances in your VPC by using the mount targets you create in the VPC. You can also mount your file system on your EC2-Classic instances (which are not in the VPC), but you must first link them to your VPC by using ClassicLink. For more information about using ClassicLink, see ClassicLink in the Amazon EC2 User Guide for Linux Instances.

  • You can mount an Amazon EFS file system from on-premises data center servers using AWS Direct Connect and VPN.

  • VPC peering within a single AWS Region when using certain Amazon EC2 instance types is supported. Inter-region VPC peering is supported for all instance types.