diff --git a/CHANGELOG.md b/CHANGELOG.md
index b60a50c715..55ff70bf1e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ CHANGELOG
   stop the compute fleet. It's now possible to update them by setting `Scheduling/SlurmSettings/QueueUpdateStrategy`
   to TERMINATE. ParallelCluster will terminate only the nodes removed during a resize of the cluster capacity
   performed through a cluster update.
+- Add support for RHEL9.
+- Add support for Rocky Linux 9 as `CustomAmi` created through `build-image` process. No public official ParallelCluster Rocky9 Linux AMI is made available at this time.
 - Remove `CommunicationParameters` from the Custom Slurm Settings deny list.
 - Add `DeploymentSettings/DisableSudoAccessForDefaultUser` parameter to disable sudo access of default user in supported OSes.
 
diff --git a/cli/src/pcluster/cli/commands/dcv_util.py b/cli/src/pcluster/cli/commands/dcv_util.py
index 53345621ff..6cd96bfe84 100644
--- a/cli/src/pcluster/cli/commands/dcv_util.py
+++ b/cli/src/pcluster/cli/commands/dcv_util.py
@@ -16,6 +16,6 @@ def get_supported_dcv_os(architecture):
     """Return a list of all the operating system supported by DCV."""
     architectures_dict = {
         "x86_64": SUPPORTED_OSES,
-        "arm64": ["alinux2", "centos7", "rhel8", "rocky8"],
+        "arm64": ["alinux2", "centos7", "rhel8", "rocky8", "rhel9", "rocky9"],
     }
     return architectures_dict.get(architecture, [])
diff --git a/cli/src/pcluster/constants.py b/cli/src/pcluster/constants.py
index 78e1d83db4..a4afbe49f1 100644
--- a/cli/src/pcluster/constants.py
+++ b/cli/src/pcluster/constants.py
@@ -23,7 +23,7 @@
 
 SUPPORTED_SCHEDULERS = ["slurm", "awsbatch"]
 SCHEDULERS_SUPPORTING_IMDS_SECURED = ["slurm"]
-SUPPORTED_OSES = ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"]
+SUPPORTED_OSES = ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"]
 SUPPORTED_OSES_FOR_SCHEDULER = {"slurm": SUPPORTED_OSES, "awsbatch": ["alinux2"]}
 DELETE_POLICY = "Delete"
 RETAIN_POLICY = "Retain"
@@ -42,6 +42,8 @@
     "ubuntu2204": {"user": "ubuntu"},
     "rhel8": {"user": "ec2-user"},
     "rocky8": {"user": "rocky"},
+    "rhel9": {"user": "ec2-user"},
+    "rocky9": {"user": "rocky"},
 }
 
 OS_TO_IMAGE_NAME_PART_MAP = {
@@ -51,6 +53,8 @@
     "ubuntu2204": "ubuntu-2204-lts-hvm",
     "rhel8": "rhel8-hvm",
     "rocky8": "rocky8-hvm",
+    "rhel9": "rhel9-hvm",
+    "rocky9": "rocky9-hvm",
 }
 # We do not publicly publish/release Parallelcluster AMI of below OSSes
 PRIVATE_OSES = ["rocky8"]
diff --git a/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml b/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
index eca3fdca8b..c2dd9d10d1 100644
--- a/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
@@ -94,6 +94,10 @@ phases:
                 OS='rhel8'
               elif [ `echo "${!RELEASE}" | grep '^rocky\.8'` ]; then
                 OS='rocky8'
+              elif [ `echo "${!RELEASE}" | grep '^rhel\.9'` ]; then
+                OS='rhel9'
+              elif [ `echo "${!RELEASE}" | grep '^rocky\.9'` ]; then
+                OS='rocky9'
               else
                 echo "Operating System '${!RELEASE}' is not supported. Failing build."
                 exit {{ FailExitCode }}
@@ -153,10 +157,10 @@ phases:
                   exit {{ FailExitCode }}
                 fi
 
-                # This component only supports aarch64 CPUs on Amazon Linux 2, Ubuntu2004, Ubuntu2204, Centos7, RHEL8 and Rocky8
+                # This component only supports aarch64 CPUs on Amazon Linux 2, Ubuntu2004, Ubuntu2204, Centos7, RHEL8, Rocky8, RHEL9 and Rocky9
                 ARCH=$(uname -m)
                 if [[ `echo ${!ARCH}` == 'aarch64' ]]; then
-                  if [ `echo "${!RELEASE}" | grep -Ev '^(amzn\.2|centos\.7|ubuntu\.20\.04|ubuntu\.22\.04|rhel\.8|rocky\.8)'` ]; then
+                  if [ `echo "${!RELEASE}" | grep -Ev '^(amzn\.2|centos\.7|ubuntu\.20\.04|ubuntu\.22\.04|rhel\.8|rocky\.8|rhel\.9|rocky\.9)'` ]; then
                     echo "This component does not support '${!RELEASE}' on ARM64 CPUs. Failing build."
                     exit {{ FailExitCode }}
                   fi
diff --git a/cli/src/pcluster/resources/imagebuilder/parallelcluster_tag.yaml b/cli/src/pcluster/resources/imagebuilder/parallelcluster_tag.yaml
index 79bc885782..743f15331f 100644
--- a/cli/src/pcluster/resources/imagebuilder/parallelcluster_tag.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/parallelcluster_tag.yaml
@@ -57,6 +57,10 @@ phases:
                 OS='rhel8'
               elif [ $(echo "${RELEASE}" | grep '^rocky\.8') ]; then
                 OS='rocky8'
+              elif [ $(echo "${RELEASE}" | grep '^rhel\.9') ]; then
+                OS='rhel9'
+              elif [ $(echo "${RELEASE}" | grep '^rocky\.9') ]; then
+                OS='rocky9'
               fi
 
               echo ${OS}
diff --git a/cli/src/pcluster/resources/imagebuilder/parallelcluster_test.yaml b/cli/src/pcluster/resources/imagebuilder/parallelcluster_test.yaml
index d2c683e2ad..bb62602043 100644
--- a/cli/src/pcluster/resources/imagebuilder/parallelcluster_test.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/parallelcluster_test.yaml
@@ -46,6 +46,10 @@ phases:
                 OS='rhel8'
               elif [ `echo "${RELEASE}" | grep '^rocky\.8'` ]; then
                 OS='rocky8'
+              elif [ `echo "${RELEASE}" | grep '^rhel\.9'` ]; then
+                OS='rhel9'
+              elif [ `echo "${RELEASE}" | grep '^rocky\.9'` ]; then
+                OS='rocky9'
               else
                 echo "Operating System '${RELEASE}' is not supported. Failing build." && exit 1
               fi
diff --git a/cli/src/pcluster/resources/imagebuilder/parallelcluster_validate.yaml b/cli/src/pcluster/resources/imagebuilder/parallelcluster_validate.yaml
index f340def9ec..c30a8f39a4 100644
--- a/cli/src/pcluster/resources/imagebuilder/parallelcluster_validate.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/parallelcluster_validate.yaml
@@ -46,6 +46,10 @@ phases:
                 OS='rhel8'
               elif [ `echo "${RELEASE}" | grep '^rocky\.8'` ]; then
                 OS='rocky8'
+              elif [ `echo "${RELEASE}" | grep '^rhel\.9'` ]; then
+                OS='rhel9'
+              elif [ `echo "${RELEASE}" | grep '^rocky\.9'` ]; then
+                OS='rocky9'
               else
                 echo "Operating System '${RELEASE}' is not supported. Failing build." && exit 1
               fi
@@ -126,7 +130,7 @@ phases:
               set -v
               ARCHITECTURE='{{ validate.OperatingSystemArchitecture.outputs.stdout }}'
               OS='{{ validate.OperatingSystemName.outputs.stdout }}'
-              if [ ${ARCHITECTURE} == 'arm64' ] && [[ ${OS} =~ ^(ubuntu(20|22)04|alinux2|rhel8|rocky8)$ ]] || [ ${ARCHITECTURE} == 'x86_64' ]; then
+              if [ ${ARCHITECTURE} == 'arm64' ] && [[ ${OS} =~ ^(ubuntu(20|22)04|alinux2|rhel8|rocky8|rhel9|rocky9)$ ]] || [ ${ARCHITECTURE} == 'x86_64' ]; then
                 echo "true"
               else
                 echo "false"
diff --git a/cli/src/pcluster/resources/imagebuilder/update_and_reboot.yaml b/cli/src/pcluster/resources/imagebuilder/update_and_reboot.yaml
index 4e911fa6d3..ebb464f23a 100644
--- a/cli/src/pcluster/resources/imagebuilder/update_and_reboot.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/update_and_reboot.yaml
@@ -47,6 +47,10 @@ phases:
                 OS='rhel8'
               elif [ `echo "${!RELEASE}" | grep '^rocky\.8'` ]; then
                 OS='rocky8'
+              elif [ `echo "${!RELEASE}" | grep '^rhel\.9'` ]; then
+                OS='rhel9'
+              elif [ `echo "${!RELEASE}" | grep '^rocky\.9'` ]; then
+                OS='rocky9'
               else
                 echo "Operating System '${!RELEASE}' is not supported. Failing build."
                 exit {{ FailExitCode }}
@@ -84,10 +88,10 @@ phases:
                 exit {{ FailExitCode }}
               fi
 
-              # This component only supports aarch64 CPUs on Amazon Linux 2, Ubuntu2004, Ubuntu2204, Centos7, RHEL8 and Rocky8
+              # This component only supports aarch64 CPUs on Amazon Linux 2, Ubuntu2004, Ubuntu2204, Centos7, RHEL8, Rocky8, RHEL9 and Rocky9
               ARCH=$(uname -m)
               if [[ `echo ${!ARCH}` == 'aarch64' ]]; then
-                if [ `echo "${!RELEASE}" | grep -Ev '^(amzn\.2|centos\.7|ubuntu\.20\.04|ubuntu\.22\.04|rhel\.8|rocky\.8)'` ]; then
+                if [ `echo "${!RELEASE}" | grep -Ev '^(amzn\.2|centos\.7|ubuntu\.20\.04|ubuntu\.22\.04|rhel\.8|rocky\.8|rhel\.9|rocky\.9)'` ]; then
                   echo "This component does not support '${!RELEASE}' on ARM64 CPUs. Failing build."
                   exit {{ FailExitCode }}
                 fi
@@ -238,20 +242,9 @@ phases:
               if [[ ${!PLATFORM} == RHEL ]]; then
                 yum -y update
 
-                if [[ ${!OS} == "rhel8" ]] || [[ ${!OS} == "rocky8" ]] ; then
-                  # package-cleanup has changed in RHEL8 and it works differently
-                  # RHEL8 keeps at least 2 kernel for fallback reason https://access.redhat.com/solutions/1227
-                  # The kernel cleanup should be performed manually
-
-                  # get the default kernel for the next boot
-                  LAST_KERNEL_VERSION=$(grubby --default-kernel | sed -e "s/.*-\(4.18.0-.*\).$(uname -m)/\1/g")
-
-                  # get all the installed kernel versions except the one for the next boot
-                  KERNEL_VERSIONS_CLEANUP=$(rpm -q --qf "%{VERSION}-%{RELEASE}\n" kernel | grep -v "$LAST_KERNEL_VERSION")
-                  for VERSION in $KERNEL_VERSIONS_CLEANUP; do
-                    echo "Removing kernel-$VERSION kernel-core-$VERSION kernel-modules-$VERSION"
-                    rpm -e kernel-$VERSION kernel-core-$VERSION kernel-modules-$VERSION;
-                  done
+                if [[ ${!OS} == "rhel8" ]] || [[ ${!OS} == "rocky8" ]] || [[ ${!OS} == "rhel9" ]] || [[ ${!OS} == "rocky9" ]] ; then
+                  # package-cleanup has changed in RHEL8 and it works differently https://access.redhat.com/solutions/1227
+                  yum remove $(yum repoquery --installonly --latest-limit=-2 -q)
                 else
                   package-cleanup -y --oldkernels --count=1
                 fi
diff --git a/cli/src/pcluster/templates/cw_dashboard_builder.py b/cli/src/pcluster/templates/cw_dashboard_builder.py
index 883397b6dc..13d8b1d7f2 100644
--- a/cli/src/pcluster/templates/cw_dashboard_builder.py
+++ b/cli/src/pcluster/templates/cw_dashboard_builder.py
@@ -733,7 +733,7 @@ def _add_cw_log(self):
                 [
                     self._new_cw_log_widget(
                         title="system-messages",
-                        conditions=[Condition(["alinux2", "centos7", "rhel8", "rocky8"], base_os)],
+                        conditions=[Condition(["alinux2", "centos7", "rhel8", "rocky8", "rhel9", "rocky9"], base_os)],
                         filters=[self._new_filter(pattern=f"{head_private_ip}.*system-messages")],
                     ),
                     self._new_cw_log_widget(
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_disabled_efa_no_placement_group/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_disabled_efa_no_placement_group/output.txt
index 3c767bcb38..78340cf77f 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_disabled_efa_no_placement_group/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_disabled_efa_no_placement_group/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 The EC2 instance selected supports enhanced networking capabilities using Elastic Fabric Adapter (EFA). EFA enables you to run applications requiring high levels of inter-node communications at scale on AWS at no additional charge (https://docs.aws.amazon.com/parallelcluster/latest/ug/efa-v3.html).
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_efa_not_supported/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_efa_not_supported/output.txt
index c4d16ff91e..b87947ec7b 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_efa_not_supported/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_efa_not_supported/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_default_placement_group/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_default_placement_group/output.txt
index 40a5362b67..92157a83c9 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_default_placement_group/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_default_placement_group/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 The EC2 instance selected supports enhanced networking capabilities using Elastic Fabric Adapter (EFA). EFA enables you to run applications requiring high levels of inter-node communications at scale on AWS at no additional charge (https://docs.aws.amazon.com/parallelcluster/latest/ug/efa-v3.html).
 Enabling EFA requires compute instances to be placed within a Placement Group. Please specify an existing Placement Group name or leave it blank for ParallelCluster to create one.
 Allowed values for VPC ID:
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_existing_placement_group/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_existing_placement_group/output.txt
index 40a5362b67..92157a83c9 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_existing_placement_group/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_existing_placement_group/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 The EC2 instance selected supports enhanced networking capabilities using Elastic Fabric Adapter (EFA). EFA enables you to run applications requiring high levels of inter-node communications at scale on AWS at no additional charge (https://docs.aws.amazon.com/parallelcluster/latest/ug/efa-v3.html).
 Enabling EFA requires compute instances to be placed within a Placement Group. Please specify an existing Placement Group name or leave it blank for ParallelCluster to create one.
 Allowed values for VPC ID:
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_non_existent_placement_group/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_non_existent_placement_group/output.txt
index 79f824d180..6ceb079b46 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_non_existent_placement_group/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_enabled_efa_non_existent_placement_group/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 The EC2 instance selected supports enhanced networking capabilities using Elastic Fabric Adapter (EFA). EFA enables you to run applications requiring high levels of inter-node communications at scale on AWS at no additional charge (https://docs.aws.amazon.com/parallelcluster/latest/ug/efa-v3.html).
 Enabling EFA requires compute instances to be placed within a Placement Group. Please specify an existing Placement Group name or leave it blank for ParallelCluster to create one.
 ERROR: non-existent-test-pg is not an acceptable value for Placement Group name
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_filtered_subnets_by_az/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_filtered_subnets_by_az/output.txt
index 95614586c5..bc322d589d 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_filtered_subnets_by_az/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_filtered_subnets_by_az/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_automation_no_awsbatch_no_errors/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_automation_no_awsbatch_no_errors/output.txt
index c4d16ff91e..b87947ec7b 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_automation_no_awsbatch_no_errors/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_automation_no_awsbatch_no_errors/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_input_no_automation_no_errors/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_input_no_automation_no_errors/output.txt
index 8491bc28fc..36e30a95bf 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_input_no_automation_no_errors/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_no_input_no_automation_no_errors/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors/output.txt
index f8ce58a54d..09a69811cf 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors_empty_vpc/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors_empty_vpc/output.txt
index 944a45aabb..152124bb11 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors_empty_vpc/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_subnet_automation_no_awsbatch_no_errors_empty_vpc/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_awsbatch_no_errors/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_awsbatch_no_errors/output.txt
index 0c67e1bdcb..1811eefc71 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_awsbatch_no_errors/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_awsbatch_no_errors/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for Availability Zone:
 1. eu-west-1a
 2. eu-west-1b
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region/output.txt
index 961f70a8f9..e5c1844997 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 There are no VPC for the given region. Starting automatic creation of VPC and subnets...
 Allowed values for Availability Zone:
 1. eu-west-1a
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region_public/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region_public/output.txt
index 961f70a8f9..e5c1844997 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region_public/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_vpc_automation_no_vpc_in_region_public/output.txt
@@ -36,6 +36,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 There are no VPC for the given region. Starting automatic creation of VPC and subnets...
 Allowed values for Availability Zone:
 1. eu-west-1a
diff --git a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_with_region_arg/output.txt b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_with_region_arg/output.txt
index ef47c4e193..e8c27189b4 100644
--- a/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_with_region_arg/output.txt
+++ b/cli/tests/pcluster/cli/configure/test_pcluster_configure/test_with_region_arg/output.txt
@@ -19,6 +19,8 @@ Allowed values for Operating System:
 4. ubuntu2204
 5. rhel8
 6. rocky8
+7. rhel9
+8. rocky9
 Allowed values for VPC ID:
   #  id            name                                 number_of_subnets
 ---  ------------  ---------------------------------  -------------------
diff --git a/cli/tests/pcluster/test_utils.py b/cli/tests/pcluster/test_utils.py
index 2a092ab0b9..ad92f28559 100644
--- a/cli/tests/pcluster/test_utils.py
+++ b/cli/tests/pcluster/test_utils.py
@@ -86,8 +86,8 @@ def test_generate_random_prefix():
 @pytest.mark.parametrize(
     "architecture, supported_oses",
     [
-        ("x86_64", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"]),
-        ("arm64", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"]),
+        ("x86_64", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"]),
+        ("arm64", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"]),
     ],
 )
 def test_get_supported_os_for_architecture(architecture, supported_oses):
@@ -100,7 +100,7 @@ def test_get_supported_os_for_architecture(architecture, supported_oses):
 @pytest.mark.parametrize(
     "scheduler, supported_oses",
     [
-        ("slurm", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"]),
+        ("slurm", ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"]),
         ("awsbatch", ["alinux2"]),
     ],
 )
diff --git a/cloudformation/storage/storage-stack.yaml b/cloudformation/storage/storage-stack.yaml
index f4b03c4f01..ca36d8c889 100644
--- a/cloudformation/storage/storage-stack.yaml
+++ b/cloudformation/storage/storage-stack.yaml
@@ -195,6 +195,7 @@ Resources:
     Condition: CreateFsxLustre
     Properties:
       FileSystemType: LUSTRE
+      FileSystemTypeVersion: '2.12'
       LustreConfiguration:
         DeploymentType: PERSISTENT_1
         ExportPath: !Ref FsxLustreExportPath
diff --git a/pc_support/os_3.9.0.json b/pc_support/os_3.9.0.json
index 9c80eb05d0..93e50d2692 100644
--- a/pc_support/os_3.9.0.json
+++ b/pc_support/os_3.9.0.json
@@ -19,6 +19,10 @@
     {
       "name": "rhel8",
       "description": "Red Hat Enterprise Linux 8"
+    },
+    {
+      "name": "rhel9",
+      "description": "Red Hat Enterprise Linux 9"
     }
   ]
 }
diff --git a/tests/integration-tests/configs/common.jinja2 b/tests/integration-tests/configs/common.jinja2
index b852609e5c..d499659512 100644
--- a/tests/integration-tests/configs/common.jinja2
+++ b/tests/integration-tests/configs/common.jinja2
@@ -5,19 +5,19 @@
 {%- set SCHEDULERS_ALL = ["slurm", "awsbatch"] -%}
 {%- set SCHEDULERS_TRAD = ["slurm"] -%}
 {%- set OSS_BATCH = ["alinux2"] -%}
-{%- set OSS_COMMERCIAL_X86 = ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8"] -%}
-{%- set OSS_CHINA_X86 = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"] -%}
-{%- set OSS_GOVCLOUD_X86 = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8"] -%}
-{%- set OSS_COMMERCIAL_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8"] -%}
-{%- set OSS_CHINA_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8"] -%}
-{%- set OSS_GOVCLOUD_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8"] -%}
+{%- set OSS_COMMERCIAL_X86 = ["alinux2", "centos7", "ubuntu2004", "ubuntu2204", "rhel8", "rhel9"] -%}
+{%- set OSS_CHINA_X86 = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"] -%}
+{%- set OSS_GOVCLOUD_X86 = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rocky8", "rhel9", "rocky9"] -%}
+{%- set OSS_COMMERCIAL_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rhel9"] -%}
+{%- set OSS_CHINA_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rhel9"] -%}
+{%- set OSS_GOVCLOUD_ARM = ["alinux2", "ubuntu2004", "ubuntu2204", "rhel8", "rhel9"] -%}
 {%- set OSS_ONE_PER_DISTRO = ["centos7", "alinux2", "ubuntu2004", "rhel8", "rocky8"] -%}
 {%- set INSTANCES_DEFAULT_X86 = ["c5.xlarge"] -%}
 {%- set INSTANCES_DEFAULT_ARM = ["m6g.xlarge"] -%} # m6g.xlarge is not supported in af-south-1, eu-south-1, eu-west-3, me-south-1
 {%- set INSTANCES_DEFAULT = ["c5.xlarge", "m6g.xlarge"] -%}
 {%- set INSTANCES_EFA_SUPPORTED_X86 = ["c5n.9xlarge"] -%}
 {%- set INSTANCES_EFA_UNSUPPORTED_X86 = ["t2.micro"] -%}
-{%- set NOT_RELEASED_OSES = ["rocky8"] -%}
+{%- set NOT_RELEASED_OSES = ["rocky8", "rocky9"] -%}
 
 {%- macro instance(instance_key) -%}
     {%- if additional_instance_types_map -%}
diff --git a/tests/integration-tests/configs/common/common.yaml b/tests/integration-tests/configs/common/common.yaml
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/integration-tests/configs/develop.yaml b/tests/integration-tests/configs/develop.yaml
index 6abbce3b85..8ca5f13614 100644
--- a/tests/integration-tests/configs/develop.yaml
+++ b/tests/integration-tests/configs/develop.yaml
@@ -831,6 +831,7 @@ test-suites:
         - regions: ["eu-west-2"]
           schedulers: ["slurm"]
           oss: ["alinux2"]
+          instances: {{ common.INSTANCES_DEFAULT_X86 }}
   users:
     test_default_user_home.py::test_default_user_local_home:
       dimensions:
diff --git a/tests/integration-tests/configs/new_os.yaml b/tests/integration-tests/configs/new_os.yaml
index 67bcea24b6..a3d9a95571 100644
--- a/tests/integration-tests/configs/new_os.yaml
+++ b/tests/integration-tests/configs/new_os.yaml
@@ -201,16 +201,6 @@ test-suites:
           schedulers: ["slurm"]
   storage:
     # Commercial regions that can't test FSx: ap-northeast-1, ap-southeast-1, ap-southeast-2, eu-central-1, eu-north-1, eu-west-1, eu-west-2, us-east-1, us-east-2, us-west-1, us-west-2
-    test_fsx_lustre.py::test_fsx_lustre:
-      dimensions:
-        - regions: ["eu-west-2"]
-          instances: {{ common.INSTANCES_DEFAULT_X86 }}
-          oss: {{ NEW_OS }}
-          schedulers: ["slurm"]
-        - regions: ["eu-north-1"]
-          instances: {{ common.INSTANCES_DEFAULT_ARM }}
-          oss: {{ NEW_OS }}
-          schedulers: ["slurm"]
     # The checks performed in test_multiple_fsx is the same as test_fsx_lustre.
     # We should consider this when assigning dimensions to each test.
     test_fsx_lustre.py::test_multiple_fsx:
@@ -295,3 +285,4 @@ test-suites:
         - regions: [ "eu-west-2" ]
           schedulers: [ "slurm" ]
           oss: {{ NEW_OS }}
+          instances: {{ common.INSTANCES_DEFAULT_X86 }}
diff --git a/tests/integration-tests/conftest.py b/tests/integration-tests/conftest.py
index febbe96dd9..2135528424 100644
--- a/tests/integration-tests/conftest.py
+++ b/tests/integration-tests/conftest.py
@@ -1407,14 +1407,14 @@ def odcr_stack(
         AvailabilityZone=availability_zone_1,
         InstanceCount=2,
         InstancePlatform="Linux/UNIX",
-        InstanceType="t3.micro",
+        InstanceType="c5.xlarge",
     )
     az2_odcr = ec2.CapacityReservation(
         "az2Odcr",
         AvailabilityZone=availability_zone_2,
         InstanceCount=2,
         InstancePlatform="Linux/UNIX",
-        InstanceType="t3.micro",
+        InstanceType="c5.xlarge",
     )
     multi_az_odcr_group = resourcegroups.Group(
         "multiAzOdcrGroup",
diff --git a/tests/integration-tests/remote_command_executor.py b/tests/integration-tests/remote_command_executor.py
index 901e494d32..8c314fc3a8 100644
--- a/tests/integration-tests/remote_command_executor.py
+++ b/tests/integration-tests/remote_command_executor.py
@@ -233,7 +233,7 @@ def get_remote_files(self, *args, **kwargs):
     def clear_log_file(self, path: str):
         """Clear a log file in a specific path."""
 
-        self.run_remote_command(f"sudo truncate -s 0 {path}")
+        self.run_remote_command(f"sudo -u {self.get_user_to_operate_on_file(path)} truncate -s 0 {path}")
 
     def clear_clustermgtd_log(self):
         """Clear clustermgtd log file."""
@@ -249,3 +249,13 @@ def clear_slurmctld_log(self):
         """Clear slurmctld log file."""
 
         self.clear_log_file("/var/log/slurmctld.log")
+
+    def get_user_to_operate_on_file(self, path):
+        """Get the user to operate on the file."""
+
+        file_owner_result = self.run_remote_command(f"stat -c '%U' {path}", raise_on_error=False)
+        if file_owner_result.failed:
+            # If failed, it means the `path` does not contain files/directories. Use root as the default owner.
+            return "root"
+        else:
+            return file_owner_result.stdout.strip()
diff --git a/tests/integration-tests/tests/cloudwatch_logging/test_cloudwatch_logging.py b/tests/integration-tests/tests/cloudwatch_logging/test_cloudwatch_logging.py
index 6ec9cbbafb..5f298f6222 100644
--- a/tests/integration-tests/tests/cloudwatch_logging/test_cloudwatch_logging.py
+++ b/tests/integration-tests/tests/cloudwatch_logging/test_cloudwatch_logging.py
@@ -150,9 +150,9 @@ def _base_os_to_platform(base_os):
         # cookbooks/aws-parallelcluster-config/files/default/cloudwatch the configurations refers to:
         # * "alinux2" as platform "amazon"
         # * "rhel8" as platform "redhat"
-        if base_os == "alinux2":
+        if "alinux" in base_os:
             return "amazon"
-        elif base_os == "rhel8":
+        elif "rhel" in base_os:
             return "redhat"
         else:
             return base_os.rstrip(string.digits)
@@ -356,7 +356,8 @@ def _write_dummy_message_to_log(self, log_path, node_type):
         dummy_log_entry = "CloudWatch logs integ test - ensuring critical log file is not empty"
         self._run_command_on_head_node(f"echo '{dummy_log_entry}' > {dummy_log_message_path}")
         # Append the dummy entry to the log
-        cmd = f"sudo tee -a {log_path} < {dummy_log_message_path}"
+        log_file_user = self.remote_command_executor.get_user_to_operate_on_file(log_path)
+        cmd = f"sudo -u {log_file_user} tee -a {log_path} < {dummy_log_message_path}"
         if node_type == HEAD_NODE_ROLE_NAME:
             self._run_command_on_head_node(cmd)
         elif node_type == COMPUTE_NODE_ROLE_NAME:
diff --git a/tests/integration-tests/tests/common/utils.py b/tests/integration-tests/tests/common/utils.py
index b02a04ebf1..4633a7660d 100644
--- a/tests/integration-tests/tests/common/utils.py
+++ b/tests/integration-tests/tests/common/utils.py
@@ -31,6 +31,8 @@
 
 SYSTEM_ANALYZER_SCRIPT = pathlib.Path(__file__).parent / "data/system-analyzer.sh"
 
+RHEL_OWNERS = ["309956199498", "841258680906", "219670896067"]
+
 OS_TO_OFFICIAL_AMI_NAME_OWNER_MAP = {
     "alinux2": {"name": "amzn2-ami-kernel-5.10-hvm-*.*.*.*-*-gp2", "owners": ["amazon"]},
     # TODO: use marketplace AMI if possible
@@ -46,9 +48,11 @@
     # FIXME: unpin once Lustre client is available for RHEL8.9
     # FIXME: when fixed upstream, unpin the timestamp introduced because the `kernel-devel` package was missing for
     # the kernel released in 20231127 RHEL 8.8 AMI
-    "rhel8": {"name": "RHEL-8.8*_HVM-202309*", "owners": ["309956199498", "841258680906", "219670896067"]},
+    "rhel8": {"name": "RHEL-8.8*_HVM-202309*", "owners": RHEL_OWNERS},
     # FIXME: unpin once Lustre client is available for Rocky 8.9
     "rocky8": {"name": "Rocky-8-EC2-Base-8.8*", "owners": ["792107900819"]},  # TODO add china and govcloud accounts
+    "rhel9": {"name": "RHEL-9.3*_HVM-*", "owners": RHEL_OWNERS},
+    "rocky9": {"name": "Rocky-9-EC2-Base-9.3*", "owners": ["792107900819"]},  # TODO add china and govcloud accounts
 }
 
 # Remarkable AMIs are latest deep learning base AMI and FPGA developer AMI without pcluster infrastructure
@@ -60,9 +64,11 @@
     # FIXME: unpin once Lustre client is available for RHEL8.9
     # FIXME: when fixed upstream, unpin the timestamp introduced because the `kernel-devel` package was missing for
     # the kernel released in 20231127 RHEL 8.8 AMI
-    "rhel8": {"name": "RHEL-8.8*_HVM-202309*", "owners": ["309956199498", "841258680906", "219670896067"]},
+    "rhel8": {"name": "RHEL-8.8*_HVM-202309*", "owners": RHEL_OWNERS},
     # FIXME: unpin once Lustre client is available for Rocky 8.9
     "rocky8": {"name": "Rocky-8-EC2-Base-8.8*", "owners": ["792107900819"]},  # TODO add china and govcloud accounts
+    "rhel9": {"name": "RHEL-9.3*_HVM-*", "owners": RHEL_OWNERS},
+    "rocky9": {"name": "Rocky-9-EC2-Base-9.3*", "owners": ["792107900819"]},  # TODO add china and govcloud accounts
 }
 
 OS_TO_KERNEL4_AMI_NAME_OWNER_MAP = {
@@ -79,6 +85,8 @@
     "ubuntu2204": {"name": "ubuntu-2204-lts-hvm-*-*", "owners": PCLUSTER_AMI_OWNERS},
     "rhel8": {"name": "rhel8-hvm-*-*", "owners": PCLUSTER_AMI_OWNERS},
     "rocky8": {"name": "rocky8-hvm-*-*", "owners": PCLUSTER_AMI_OWNERS},
+    "rhel9": {"name": "rhel9-hvm-*-*", "owners": PCLUSTER_AMI_OWNERS},
+    "rocky9": {"name": "rocky9-hvm-*-*", "owners": PCLUSTER_AMI_OWNERS},
 }
 
 AMI_TYPE_DICT = {
diff --git a/tests/integration-tests/tests/storage/test_fsx_lustre.py b/tests/integration-tests/tests/storage/test_fsx_lustre.py
index dfeacdc81e..6dc156bdb7 100644
--- a/tests/integration-tests/tests/storage/test_fsx_lustre.py
+++ b/tests/integration-tests/tests/storage/test_fsx_lustre.py
@@ -525,6 +525,7 @@ def _create_fsx_lustre_volume_ids(num_existing_fsx_lustre, fsx_factory, import_p
             DeploymentType="PERSISTENT_1",
             PerUnitStorageThroughput=200,
         ),
+        FileSystemTypeVersion="2.12",
     )
 
 
diff --git a/tests/integration-tests/tests/update/test_update.py b/tests/integration-tests/tests/update/test_update.py
index 7c10972cca..fc6fbb23c1 100644
--- a/tests/integration-tests/tests/update/test_update.py
+++ b/tests/integration-tests/tests/update/test_update.py
@@ -1536,7 +1536,7 @@ def _test_shared_storage_rollback(
             boto3.client("fsx", region).describe_file_systems(FileSystemIds=managed_fsx)
 
 
-@pytest.mark.usefixtures("os")
+@pytest.mark.usefixtures("os", "instance")
 def test_multi_az_create_and_update(
     region, pcluster_config_reader, clusters_factory, odcr_stack, scheduler_commands_factory, test_datadir
 ):
diff --git a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_create.config.yaml b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_create.config.yaml
index 2fd8010660..e386765228 100644
--- a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_create.config.yaml
+++ b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_create.config.yaml
@@ -1,7 +1,7 @@
 Image:
   Os: {{ os }}
 HeadNode:
-  InstanceType: t2.micro
+  InstanceType: {{ instance }}
   Networking:
     SubnetId: {{ public_subnet_ids[0] }}
   Ssh:
@@ -13,7 +13,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-1
           Instances:
-            - InstanceType: t3.micro
+            - InstanceType: {{ instance }}
           MinCount: 6
           MaxCount: 10
           CapacityReservationTarget:
@@ -26,7 +26,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-2
           Instances:
-            - InstanceType: t2.micro
+            - InstanceType: {{ instance }}
           MinCount: 0
           MaxCount: 4
       Networking:
diff --git a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_1.config.yaml b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_1.config.yaml
index d37d29bce2..ca5a32a22b 100644
--- a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_1.config.yaml
+++ b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_1.config.yaml
@@ -1,7 +1,7 @@
 Image:
   Os: {{ os }}
 HeadNode:
-  InstanceType: t2.micro
+  InstanceType: {{ instance }}
   Networking:
     SubnetId: {{ public_subnet_ids[0] }}
   Ssh:
@@ -13,7 +13,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-1
           Instances:
-            - InstanceType: t3.micro
+            - InstanceType: {{ instance }}
           MinCount: 6
           MaxCount: 10
           CapacityReservationTarget:
@@ -26,7 +26,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-2
           Instances:
-            - InstanceType: t2.micro
+            - InstanceType: {{ instance }}
           MinCount: 0
           MaxCount: 4
       Networking:
diff --git a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_2.config.yaml b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_2.config.yaml
index 2fd8010660..e386765228 100644
--- a/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_2.config.yaml
+++ b/tests/integration-tests/tests/update/test_update/test_multi_az_create_and_update/pcluster_update_2.config.yaml
@@ -1,7 +1,7 @@
 Image:
   Os: {{ os }}
 HeadNode:
-  InstanceType: t2.micro
+  InstanceType: {{ instance }}
   Networking:
     SubnetId: {{ public_subnet_ids[0] }}
   Ssh:
@@ -13,7 +13,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-1
           Instances:
-            - InstanceType: t3.micro
+            - InstanceType: {{ instance }}
           MinCount: 6
           MaxCount: 10
           CapacityReservationTarget:
@@ -26,7 +26,7 @@ Scheduling:
       ComputeResources:
         - Name: compute-resource-2
           Instances:
-            - InstanceType: t2.micro
+            - InstanceType: {{ instance }}
           MinCount: 0
           MaxCount: 4
       Networking:
diff --git a/tests/integration-tests/utils.py b/tests/integration-tests/utils.py
index c02585d624..b16e62511a 100644
--- a/tests/integration-tests/utils.py
+++ b/tests/integration-tests/utils.py
@@ -551,6 +551,8 @@ def get_username_for_os(os):
         "ubuntu2204": "ubuntu",
         "rhel8": "ec2-user",
         "rocky8": "rocky",
+        "rhel9": "ec2-user",
+        "rocky9": "rocky",
     }
     return usernames.get(os)