Amazon Elastic File System
User Guide

Amazon EFS Limits

This section describes limitations when working with Amazon EFS.

Amazon EFS Limits That Can Be Increased

Following are the limits for Amazon EFS that can be increased by contacting AWS Support.

Resource Default Limit
Number of file systems per customer account in an AWS Region 10
Throughput limit for each file system for all connected clients 3 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.

Amazon EFS Resource Limits

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

Resource Limit
Default limit on the number of file systems 10
Number of mount targets per file system per Availability Zone 1
Number of security groups per mount target 5
Number of tags per file system 50
Number of VPCs per file system 1

Limits for Client EC2 Instances

The following limits for client EC2 instances apply, assuming a Linux NFSv4.1 client.

  • The maximum throughput you can drive per Amazon EC2 instance is 250 MB/s.

  • Up to 128 active user accounts per instance may have files open at the same time.

  • Up to 32,768 files open at the same time on the instance.

  • Each unique mount on the instance 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.

  • Using Amazon EFS with Microsoft Windows Amazon EC2 instances is not supported.

Limits for Amazon EFS File Systems

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

  • Each Amazon EFS file system has a default throughput limit of 3 GB/s for all connected clients.

  • Maximum name length: 255 bytes.

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

  • Maximum number of hard links to a file 175.

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

  • Maximum directory depth: 1000 levels deep.

  • Any one particular file can have up to 87 locks across all users of the file system. You may mount a file system on one or more Amazon EC2 instances, but the maximum 87-lock limit for a file applies.

  • 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.

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.

  • Some AWS accounts created before 2012 might have access to Availability Zones in us-east-1 that do not support creating mount targets. If you are unable to create a mount target in the region, try a different Availability Zone in that region. However, 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.

  • You mount your file system from EC2 instances in your VPC via 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 via the ClassicLink. For more information about using ClassicLink, see ClassicLink in the Amazon EC2 User Guide for Linux Instances.

  • An Amazon EFS file system can be mounted from on-premises datacenter servers using AWS Direct Connect. However, other VPC private connectivity mechanisms such as a VPN connection and VPC peering are not supported.