Image section

(Required) Defines the operating system for the cluster.

Image:
  Os: string
  CustomAmi: string

Image properties

Os (Required, String)

Specifies the operating system to use for the cluster. The supported values are alinux2, alinux2023, ubuntu2204, ubuntu2004, rhel8, rocky8, rhel9, rocky9.

Note

RedHat Enterprise Linux 8.7 (rhel8) is added starting in AWS ParallelCluster version 3.6.0.

If you configure your cluster to use rhel, the on-demand cost for any instance type is higher than when you configure your cluster to use other supported operation systems. For more information about pricing, see On-Demand Pricing and How is Red Hat Enterprise Linux on Amazon EC2 offered and priced?.

RedHat Enterprise Linux 9 (rhel9) is added starting in AWS ParallelCluster version 3.9.0.

All AWS commercial Regions support all of the following operating systems.

Partition (AWS Regions)	alinux2	ubuntu2204 and ubuntu2004	rhel8	rhel9	alinux2023
Commercial (All AWS Regions not specifically mentioned)	True	True	True	True	True
AWS GovCloud (US-East) (us-gov-east-1)	True	True	True	True	True
AWS GovCloud (US-West) (us-gov-west-1)	True	True	True	True	True
China (Beijing) (cn-north-1)	True	True	True	True	True
China (Ningxia) (cn-northwest-1)	True	True	True	True	True

Update policy: If this setting is changed, the update is not allowed.

Note

AWS ParallelCluster 3.8.0 supports Rocky Linux 8, but pre-built Rocky Linux 8 AMIs (for x86 and ARM architectures) are not available. AWS ParallelCluster 3.8.0 supports creating clusters with Rocky Linux 8 using custom AMIs. For more information refer to Operating system considerations. AWS ParallelCluster 3.9.0 supports Rocky Linux 9, but pre-built Rocky Linux 9 AMIs (for x86 and ARM architectures) are not available. AWS ParallelCluster 3.9.0 supports creating clusters with Rocky Linux 9 using custom AMIs. For more information refer to Operating System Considerations.

CustomAmi (Optional, String)

Specifies the ID of a custom AMI to use for the head and compute nodes instead of the default AMI. For more information, see AWS ParallelCluster AMI customization.

If the custom AMI requires additional permissions for its launch, these permissions must be added to both the user and head node policies.

For example, if a custom AMI has an encrypted snapshot associated with it, the following additional policies are required in both the user and head node policies:

{
   "Version": "2012-10-17",
   "Statement": [
       {
           "Effect": "Allow",
           "Action": [
               "kms:DescribeKey",
               "kms:ReEncrypt*",
               "kms:CreateGrant",
               "kms:Decrypt"
           ],
           "Resource": [
               "arn:aws:kms:<AWS_REGION>:<AWS_ACCOUNT_ID>:key/<AWS_KMS_KEY_ID>"
           ]                                                    
       }
   ]
}

To build a RedHat Enterprise Linux custom AMI, you must configure the OS for installing the packages that are provided by the RHUI (AWS) repositories: rhel-<version>-baseos-rhui-rpms, rhel-<version>-appstream-rhui-rpms, and codeready-builder-for-rhel-<version>-rhui-rpms. Moreover, the repositories on the custom AMI must contain kernel-devel packages on the same version as the running kernel version. kernel.

Known limitations:

• Only RHEL 8.2 and later versions support FSx for Lustre.

• RHEL 8.7 kernel version 4.18.0-425.3.1.el8 doesn't support FSx for Lustre.

• Only RHEL 8.4 and later versions support EFA.

• AL23 doesn't support NICE DCV, as it doesn't include a graphical desktop environment, which is required to run NICE DCV. For more information, see the official NICE DCV documentation.

To troubleshoot custom AMI validation warnings, see Troubleshooting custom AMI issues.

Update policy: If this setting is changed, the update is not allowed.