Support NVIDIA-Imex with p6e-gb200 instance
This tutorial shows you how to get started with AWS ParallelCluster on P6e-GB200, to leverage the
highest GPU performance for AI training and inference.
p6e-gb200.36xlarge instances are only available via P6e-GB200 UltraServersu-p6e-gb200x72 is Ultraserver Size and p6e-gb200.36xlarge is the InstanceType which forms
the ultraserver. On purchasing an Ultraserver u-p6e-gb200x72 it will be available
through a EC2 Capacity Blocks for MLp6e-gb200.36xlarge instances. To learn more, see P6e-GB200
AWS ParallelCluster version 3.14.0:
-
provides the complete NVIDIA software stack (drivers, CUDA, EFA, NVIDIA-IMEX) required by this instance type
-
creates nvidia-imex configurations for P6e-GB200 ultraserver
-
enables and starts the
nvidia-imexservice for P6e-GB200 ultraserver -
configures the Slurm Block topology plugin so that every P6e-GB200 Ultraserver (an EC2 Capacity Block) is a Slurm Block with the right size (see the Release notes and document history entry for version 3.14.0).
However, GPU-to-GPU communication over NVLink requires additional configurations, specifically a
nodes_config.cfgnodes_config.cfg
Note
P6e-GB200 is supported starting with AWS ParallelCluster v3.14.0 on Amazon Linux 2023, Ubuntu 22.04,
and Ubuntu 24.04. For detailed software versions and an updated list of supported distributions, see the
AWS ParallelCluster
changelog
Create a Prolog Script to manage NVIDIA-Imex
Limitation:
-
This prolog script will run on submission of an exclusive job. This is to ensure that an IMEX re-start does not disrupt any running jobs on p6e-Gb200 nodes that belong to an IMEX domain.
Below is the 91_nvidia_imex_prolog.sh script you should configure as a prolog in Slurm.
It is used to automatically update the nvidia-imex configuration on compute nodes. The script's name has
a prefix of 91 to adhere to
SchedMD's naming convention
Note
This script will not be executed in case multiple jobs are started concurrently on the same
nodes, therefore we suggest to use the --exclusive flag on submission.
#!/usr/bin/env bash # This prolog script configures the NVIDIA IMEX on compute nodes involved in the job execution. # # In particular: # - Checks whether the job is executed exclusively. # If not, it exits immediately because it requires jobs to be executed exclusively. # - Checks if it is running on a p6e-gb200 instance type. # If not, it exits immediately because IMEX must be configured only on that instance type. # - Checks if the IMEX service is enabled. # If not, it exits immediately because IMEX must be enabled to get configured. # - Creates the IMEX default channel. # For more information about IMEX channels, see https://docs.nvidia.com/multi-node-nvlink-systems/imex-guide/imexchannels.html # - Writes the private IP addresses of compute nodes into /etc/nvidia-imex/nodes_config.cfg. # - Restarts the IMEX system service. # # REQUIREMENTS: # - This prolog assumes to be run only with exclusive jobs. LOG_FILE_PATH="/var/log/parallelcluster/nvidia-imex-prolog.log" SCONTROL_CMD="/opt/slurm/bin/scontrol" IMEX_START_TIMEOUT=60 IMEX_STOP_TIMEOUT=15 ALLOWED_INSTANCE_TYPES="^(p6e-gb200)" IMEX_SERVICE="nvidia-imex" IMEX_NODES_CONFIG="/etc/nvidia-imex/nodes_config.cfg" function info() { echo "$(date "+%Y-%m-%dT%H:%M:%S.%3N") [INFO] [PID:$$] [JOB:${SLURM_JOB_ID}] $1" } function warn() { echo "$(date "+%Y-%m-%dT%H:%M:%S.%3N") [WARN] [PID:$$] [JOB:${SLURM_JOB_ID}] $1" } function error() { echo "$(date "+%Y-%m-%dT%H:%M:%S.%3N") [ERROR] [PID:$$] [JOB:${SLURM_JOB_ID}] $1" } function error_exit() { error "$1" && exit 1 } function prolog_end() { info "PROLOG End JobId=${SLURM_JOB_ID}: $0" info "----------------" exit 0 } function get_instance_type() { local token=$(curl -X PUT -s "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600") curl -s -H "X-aws-ec2-metadata-token: ${token}" http://169.254.169.254/latest/meta-data/instance-type } function return_if_unsupported_instance_type() { local instance_type=$(get_instance_type) if [[ ! ${instance_type} =~ ${ALLOWED_INSTANCE_TYPES} ]]; then info "Skipping IMEX configuration because instance type ${instance_type} does not support it" prolog_end fi } function return_if_imex_disabled() { if ! systemctl is-enabled "${IMEX_SERVICE}" &>/dev/null; then warn "Skipping IMEX configuration because system service ${IMEX_SERVICE} is not enabled" prolog_end fi } function return_if_job_is_not_exclusive() { if [[ "${SLURM_JOB_OVERSUBSCRIBE}" =~ ^(NO|TOPO)$ ]]; then info "Job is exclusive, proceeding with IMEX configuration" else info "Skipping IMEX configuration because the job is not exclusive" prolog_end fi } function get_ips_from_node_names() { local _nodes=$1 ${SCONTROL_CMD} -ao show node "${_nodes}" | sed 's/^.* NodeAddr=\([^ ]*\).*/\1/' } function get_compute_resource_name() { local _queue_name_prefix=$1 local _slurmd_node_name=$2 echo "${_slurmd_node_name}" | sed -E "s/${_queue_name_prefix}(.+)-[0-9]+$/\1/" } function reload_imex() { info "Stopping IMEX" timeout ${IMEX_STOP_TIMEOUT} systemctl stop ${IMEX_SERVICE} pkill -9 ${IMEX_SERVICE} info "Restarting IMEX" timeout ${IMEX_START_TIMEOUT} systemctl start ${IMEX_SERVICE} } function create_default_imex_channel() { info "Creating IMEX default channel" MAJOR_NUMBER=$(cat /proc/devices | grep nvidia-caps-imex-channels | cut -d' ' -f1) if [ ! -d "/dev/nvidia-caps-imex-channels" ]; then sudo mkdir /dev/nvidia-caps-imex-channels fi # Then check and create device node if [ ! -e "/dev/nvidia-caps-imex-channels/channel0" ]; then sudo mknod /dev/nvidia-caps-imex-channels/channel0 c $MAJOR_NUMBER 0 info "IMEX default channel created" else info "IMEX default channel already exists" fi } { info "PROLOG Start JobId=${SLURM_JOB_ID}: $0" return_if_job_is_not_exclusive return_if_unsupported_instance_type return_if_imex_disabled create_default_imex_channel IPS_FROM_CR=$(get_ips_from_node_names "${SLURM_NODELIST}") info "Node Names: ${SLURM_NODELIST}" info "Node IPs: ${IPS_FROM_CR}" info "IMEX Nodes Config: ${IMEX_NODES_CONFIG}" info "Updating IMEX nodes config ${IMEX_NODES_CONFIG}" echo "${IPS_FROM_CR}" > "${IMEX_NODES_CONFIG}" reload_imex prolog_end } 2>&1 | tee -a "${LOG_FILE_PATH}" | logger -t "91_nvidia_imex_prolog"
Create the HeadNode OnNodeStart Custom Action Script
Create an install_custom_action.sh custom action which will download the
aforementioned prolog script in a shared directory /opt/slurm/etc/scripts/prolog.d/
which is accessed by Compute Nodes and sets the proper permissions to be executed.
#!/bin/bash set -e echo "Executing $0" PROLOG_NVIDIA_IMEX=/opt/slurm/etc/scripts/prolog.d/91_nvidia_imex_prolog.sh aws s3 cp "s3://<Bucket>/91_nvidia_imex_prolog.sh" "${PROLOG_NVIDIA_IMEX}" chmod 0755 "${PROLOG_NVIDIA_IMEX}"
Create the cluster
Create a cluster including P6e-GB200 instances. Below you can find an example configuration
containing SlurmQueues for Ultraserver type u-p6e-gb200x72.
P6e-GB200 is currently only available in Local Zones. Some Local Zones do not support a NAT Gateway, so please follow the Connectivity options for Local Zones as ParallelCluster needs Configuring security groups for restricted environments to connect to AWS Services. Please follow the Launch instances with Capacity Blocks (CB) (AWS ParallelClusterLaunch) as Ultraservers are available only as Capacity Blocks.
HeadNode: CustomActions: OnNodeStart: Script: s3://<s3-bucket-name>/install_custom_action.sh S3Access: - BucketName: <s3-bucket-name> InstanceType: <HeadNode-instance-type> Networking: SubnetId: <subnet-abcd78901234567890> Ssh: KeyName: <Key-name> Image: Os: ubuntu2404 Scheduling: Scheduler: slurm SlurmSettings: CustomSlurmSettings: - PrologFlags: "Alloc,NoHold" - MessageTimeout: 240 SlurmQueues: - CapacityReservationTarget: CapacityReservationId: <cr-123456789012345678> CapacityType: CAPACITY_BLOCK ComputeResources: ### u-p6e-gb200x72 - DisableSimultaneousMultithreading: true Efa: Enabled: true InstanceType: p6e-gb200.36xlarge MaxCount: 18 MinCount: 18 Name: cr1 Name: q1 Networking: SubnetIds: - <subnet-1234567890123456>
Validate IMEX Setup
The 91_nvidia_imex_prolog.sh prolog will run when you submit a Slurm
job. Below is an example job to check the status NVIDIA-imex domain.
#!/bin/bash #SBATCH --job-name=nvidia-imex-status-job #SBATCH --ntasks-per-node=1 #SBATCH --output=slurm-%j.out #SBATCH --error=slurm-%j.err QUEUE_NAME="q1" COMPUTE_RES_NAME="cr1" IMEX_CONFIG_FILE="/opt/parallelcluster/shared/nvidia-imex/config_${QUEUE_NAME}_${COMPUTE_RES_NAME}.cfg" srun bash -c "/usr/bin/nvidia-imex-ctl -N -c ${IMEX_CONFIG_FILE} > result_\${SLURM_JOB_ID}_\$(hostname).out 2> result_\${SLURM_JOB_ID}_\$(hostname).err"
Check the output of the Job:
Connectivity Table Legend: I - Invalid - Node wasn't reachable, no connection status available N - Never Connected R - Recovering - Connection was lost, but clean up has not yet been triggered. D - Disconnected - Connection was lost, and clean up has been triggreed. A - Authenticating - If GSSAPI enabled, client has initiated mutual authentication. !V! - Version mismatch, communication disabled. !M! - Node map mismatch, communication disabled. C - Connected - Ready for operation 5/12/2025 06:08:10.580 Nodes: Node #0 - 172.31.48.81 - READY - Version: 570.172 Node #1 - 172.31.48.98 - READY - Version: 570.172 Node #2 - 172.31.48.221 - READY - Version: 570.172 Node #3 - 172.31.49.228 - READY - Version: 570.172 Node #4 - 172.31.50.39 - READY - Version: 570.172 Node #5 - 172.31.50.44 - READY - Version: 570.172 Node #6 - 172.31.51.66 - READY - Version: 570.172 Node #7 - 172.31.51.157 - READY - Version: 570.172 Node #8 - 172.31.52.239 - READY - Version: 570.172 Node #9 - 172.31.53.80 - READY - Version: 570.172 Node #10 - 172.31.54.95 - READY - Version: 570.172 Node #11 - 172.31.54.183 - READY - Version: 570.172 Node #12 - 172.31.54.203 - READY - Version: 570.172 Node #13 - 172.31.54.241 - READY - Version: 570.172 Node #14 - 172.31.55.59 - READY - Version: 570.172 Node #15 - 172.31.55.187 - READY - Version: 570.172 Node #16 - 172.31.55.197 - READY - Version: 570.172 Node #17 - 172.31.56.47 - READY - Version: 570.172 Nodes From\To 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 0 C C C C C C C C C C C C C C C C C C 1 C C C C C C C C C C C C C C C C C C 2 C C C C C C C C C C C C C C C C C C 3 C C C C C C C C C C C C C C C C C C 4 C C C C C C C C C C C C C C C C C C 5 C C C C C C C C C C C C C C C C C C 6 C C C C C C C C C C C C C C C C C C 7 C C C C C C C C C C C C C C C C C C 8 C C C C C C C C C C C C C C C C C C 9 C C C C C C C C C C C C C C C C C C 10 C C C C C C C C C C C C C C C C C C 11 C C C C C C C C C C C C C C C C C C 12 C C C C C C C C C C C C C C C C C C 13 C C C C C C C C C C C C C C C C C C 14 C C C C C C C C C C C C C C C C C C 15 C C C C C C C C C C C C C C C C C C 16 C C C C C C C C C C C C C C C C C C 17 C C C C C C C C C C C C C C C C C C Domain State: UP
