Launching a AWS Deep Learning AMI Instance With EFA - Deep Learning AMI

Launching a AWS Deep Learning AMI Instance With EFA

The latest Base DLAMI is ready to use with EFA and comes with the required drivers, kernel modules, libfabric, openmpi and the NCCL OFI plugin for GPU instances.

You can find the supported CUDA versions of a Base DLAMI in the release notes.


  • When running a NCCL Application using mpirun on EFA, you will have to specify the full path to the EFA supported installation as:

    /opt/amazon/openmpi/bin/mpirun <command>
  • To enable your application to use EFA, add FI_PROVIDER="efa" to the mpirun command as shown in Using EFA on the DLAMI.

Prepare an EFA Enabled Security Group

EFA requires a security group that allows all inbound and outbound traffic to and from the security group itself. For more information, see the EFA Documentation.

  1. Open the Amazon EC2 console at

  2. In the navigation pane, choose Security Groups and then choose Create Security Group.

  3. In the Create Security Group window, do the following:

    • For Security group name, enter a descriptive name for the security group, such as EFA-enabled security group.

    • (Optional) For Description, enter a brief description of the security group.

    • For VPC, select the VPC into which you intend to launch your EFA-enabled instances.

    • Choose Create.

  4. Select the security group that you created, and on the Description tab, copy the Group ID.

  5. On the Inbound and Outbound tabs, do the following:

    • Choose Edit.

    • For Type, choose All traffic.

    • For Source, choose Custom.

    • Paste the security group ID that you copied into the field.

    • Choose Save

  6. Enable inbound traffic referring to Authorizing Inbound Traffic for Your Linux Instances. If you skip this step, you won't be able to communicate with your DLAMI instance.

Launch Your Instance

EFA on the AWS Deep Learning AMI is currently supported with the following instance types and operating systems:

  • P3dn.24xlarge: Amazon Linux 2, Ubuntu 18.04

  • P4d.24xlarge: Amazon Linux 2, Ubuntu 18.04

The following section shows how to launch an EFA enabled DLAMI instance. For more information on launching an EFA enabled instance, see Launch EFA-Enabled Instances into a Cluster Placement Group.

  1. Open the Amazon EC2 console at

  2. Choose Launch Instance.

  3. On the Choose an AMI page, Select the AWS Deep Learning AMI (Ubuntu 18.04) Version 25.0

  4. On the Choose an Instance Type page, select one of the following supported instance types and then choose Next: Configure Instance Details. Refer to this link for the list of supported instances: Get started with EFA and MPI

  5. On the Configure Instance Details page, do the following:

    • For Number of instances, enter the number of EFA-enabled instances that you want to launch.

    • For Network and Subnet, select the VPC and subnet into which to launch the instances.

    • [Optional] For Placement group, select Add instance to placement group. For best performance, launch the instances within a placement group.

    • [Optional] For Placement group name, select Add to a new placement group, enter a descriptive name for the placement group, and then for Placement group strategy, select cluster.

    • Make sure to enable the “Elastic Fabric Adapter” on this page. If this option is disabled, change the subnet to one that supports your selected instance type. 

    • In the Network Interfaces section, for device eth0, choose New network interface. You can optionally specify a primary IPv4 address and one or more secondary IPv4 addresses. If you're launching the instance into a subnet that has an associated IPv6 CIDR block, you can optionally specify a primary IPv6 address and one or more secondary IPv6 addresses.

    • Choose Next: Add Storage.

  6. On the Add Storage page, specify the volumes to attach to the instances in addition to the volumes specified by the AMI (such as the root device volume), and then choose Next: Add Tags.

  7. On the Add Tags page, specify tags for the instances, such as a user-friendly name, and then choose Next: Configure Security Group.

  8. On the Configure Security Group page, for Assign a security group, select Select an existing security group, and then select the security group that you created previously.

  9. Choose Review and Launch.

  10. On the Review Instance Launch page, review the settings, and then choose Launch to choose a key pair and to launch your instances.

Verify EFA Attachment

From the Console

After launching the instance, check the instance details in the AWS Console. To do this, select the instance in the EC2 console and look at the Description Tab in the lower pane on the page. Find the parameter ‘Network Interfaces: eth0’ and click on eth0 which opens a pop-up. Make sure that ‘Elastic Fabric Adapter’ is enabled.

If EFA is not enabled, you can fix this by either:

  • Terminating the EC2 instance and launching a new one with the same steps. Make sure the EFA is attached.

  • Attach EFA to an existing instance.

    1. In the EC2 Console, go to Network Interfaces.

    2. Click on Create a Network Interface.

    3. Select the same subnet that your instance is in.

    4. Make sure to enable the ‘Elastic Fabric Adapter’ and click on Create.

    5. Go back to the EC2 Instances Tab and select your instance.

    6. Go to Actions: Instance State and stop the instance before you attach EFA.

    7. From Actions, select Networking: Attach Network Interface.

    8. Select the interface you just created and click on attach.

    9. Restart your instance.

From the Instance

The following test script is already present on the DLAMI. Run it to ensure that the kernel modules are loaded correctly.

$ fi_info -p efa

Your output should look similar to the following.

provider: efa     fabric: EFA-fe80::e5:56ff:fe34:56a8     domain: efa_0-rdm     version: 2.0     type: FI_EP_RDM     protocol: FI_PROTO_EFA provider: efa     fabric: EFA-fe80::e5:56ff:fe34:56a8     domain: efa_0-dgrm     version: 2.0     type: FI_EP_DGRAM     protocol: FI_PROTO_EFA provider: efa;ofi_rxd     fabric: EFA-fe80::e5:56ff:fe34:56a8     domain: efa_0-dgrm     version: 1.0     type: FI_EP_RDM     protocol: FI_PROTO_RXD

Verify Security Group Configuration

The following test script is already present on the DLAMI. Run it to ensure that the security group you created is configured correctly.

$ cd /opt/amazon/efa/test/ $ ./

Your output should look similar to the following.

Starting server... Starting client... bytes   #sent   #ack     total       time     MB/sec    usec/xfer   Mxfers/sec 64      10      =10      1.2k        0.02s      0.06    1123.55       0.00 256     10      =10      5k          0.00s     17.66      14.50       0.07 1k      10      =10      20k         0.00s     67.81      15.10       0.07 4k      10      =10      80k         0.00s    237.45      17.25       0.06 64k     10      =10      1.2m        0.00s    921.10      71.15       0.01 1m      10      =10      20m         0.01s   2122.41     494.05       0.00

If it stops responding or does not complete, ensure that your security group has the correct inbound/outbound rules.