Recommended single-node OpenShift cluster configuration for vDU application workloads

Use the following reference information to understand the single-node OpenShift configurations required to deploy virtual distributed unit (vDU) applications in the cluster. Configurations include cluster optimizations for high performance workloads, enabling workload partitioning, and minimizing the number of reboots required postinstallation.

Additional resources

• To deploy a single cluster by hand, see Manually installing a single-node OpenShift cluster with GitOps ZTP.

• To deploy a fleet of clusters using GitOps Zero Touch Provisioning (ZTP), see Deploying far edge sites with GitOps ZTP.

Running low latency applications on OKD

OKD enables low latency processing for applications running on commercial off-the-shelf (COTS) hardware by using several technologies and specialized hardware devices:

Real-time kernel for RHCOS

Ensures workloads are handled with a high degree of process determinism.

CPU isolation

Avoids CPU scheduling delays and ensures CPU capacity is available consistently.

NUMA-aware topology management

Aligns memory and huge pages with CPU and PCI devices to pin guaranteed container memory and huge pages to the non-uniform memory access (NUMA) node. Pod resources for all Quality of Service (QoS) classes stay on the same NUMA node. This decreases latency and improves performance of the node.

Huge pages memory management

Using huge page sizes improves system performance by reducing the amount of system resources required to access page tables.

Precision timing synchronization using PTP

Allows synchronization between nodes in the network with sub-microsecond accuracy.

Recommended cluster host requirements for vDU application workloads

Running vDU application workloads requires a bare-metal host with sufficient resources to run OKD services and production workloads.

Configuring host firmware for low latency and high performance

Bare-metal hosts require the firmware to be configured before the host can be provisioned. The firmware configuration is dependent on the specific hardware and the particular requirements of your installation.

Procedure

1. Set the UEFI/BIOS Boot Mode to UEFI.

2. In the host boot sequence order, set Hard drive first.

3. Apply the specific firmware configuration for your hardware. The following table describes a representative firmware configuration for an Intel Xeon Skylake or Intel Cascade Lake server, based on the Intel FlexRAN 4G and 5G baseband PHY reference design.

   The exact firmware configuration depends on your specific hardware and network requirements. The following sample configuration is for illustrative purposes only.

   Table 2. Sample firmware configuration for an Intel Xeon Skylake or Cascade Lake server

   Firmware setting	Configuration
   CPU Power and Performance Policy	Performance
   Uncore Frequency Scaling	Disabled
   Performance P-limit	Disabled
   Enhanced Intel SpeedStep ® Tech	Enabled
   Intel Configurable TDP	Enabled
   Configurable TDP Level	Level 2
   Intel® Turbo Boost Technology	Enabled
   Energy Efficient Turbo	Disabled
   Hardware P-States	Disabled
   Package C-State	C0/C1 state
   C1E	Disabled
   Processor C6	Disabled

Connectivity prerequisites for managed cluster networks

Before you can install and provision a managed cluster with the GitOps Zero Touch Provisioning (ZTP) pipeline, the managed cluster host must meet the following networking prerequisites:

• There must be bi-directional connectivity between the GitOps ZTP container in the hub cluster and the Baseboard Management Controller (BMC) of the target bare-metal host.

• The managed cluster must be able to resolve and reach the API hostname of the hub hostname and *.apps hostname. Here is an example of the API hostname of the hub and *.apps hostname:

  • api.hub-cluster.internal.domain.com

  • console-openshift-console.apps.hub-cluster.internal.domain.com

• The hub cluster must be able to resolve and reach the API and *.apps hostname of the managed cluster. Here is an example of the API hostname of the managed cluster and *.apps hostname:

  • api.sno-managed-cluster-1.internal.domain.com

  • console-openshift-console.apps.sno-managed-cluster-1.internal.domain.com

Workload partitioning in single-node OpenShift with GitOps ZTP

Workload partitioning configures OKD services, cluster management workloads, and infrastructure pods to run on a reserved number of host CPUs.

To configure workload partitioning with GitOps Zero Touch Provisioning (ZTP), you configure a cpuPartitioningMode field in the SiteConfig custom resource (CR) that you use to install the cluster and you apply a PerformanceProfile CR that configures the isolated and reserved CPUs on the host.

Configuring the SiteConfig CR enables workload partitioning at cluster installation time and applying the PerformanceProfile CR configures the specific allocation of CPUs to reserved and isolated sets. Both of these steps happen at different points during cluster provisioning.

The workload partitioning configuration pins the OKD infrastructure pods to the reserved CPU set. Platform services such as systemd, CRI-O, and kubelet run on the reserved CPU set. The isolated CPU sets are exclusively allocated to your container workloads. Isolating CPUs ensures that the workload has guaranteed access to the specified CPUs without contention from other applications running on the same node. All CPUs that are not isolated should be reserved.

Additional resources

• For the recommended single-node OpenShift workload partitioning configuration, see Workload partitioning.

Recommended cluster install manifests

The ZTP pipeline applies the following custom resources (CRs) during cluster installation. These configuration CRs ensure that the cluster meets the feature and performance requirements necessary for running a vDU application.

Use the SiteConfig extraManifests filter to alter the CRs that are included by default. For more information, see Advanced managed cluster configuration with SiteConfig CRs.

Workload partitioning

Single-node OpenShift clusters that run DU workloads require workload partitioning. This limits the cores allowed to run platform services, maximizing the CPU core for application payloads.

Recommended SiteConfig CR configuration for workload partitioning

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "<site_name>"
  namespace: "<site_name>"
spec:
  baseDomain: "example.com"
  cpuPartitioningMode: AllNodes (1)

Verification

Check that the applications and cluster system CPU pinning is correct. Run the following commands:

1. Open a remote shell prompt to the managed cluster:

   $ oc debug node/example-sno-1

2. Check that the user applications CPU pinning is correct:

   sh-4.4# pgrep ovn | while read i; do taskset -cp $i; done

   Example output

   pid 8481's current affinity list: 0-3
   pid 8726's current affinity list: 0-3
   pid 9088's current affinity list: 0-3
   pid 9945's current affinity list: 0-3
   pid 10387's current affinity list: 0-3
   pid 12123's current affinity list: 0-3
   pid 13313's current affinity list: 0-3

3. Check that the system applications CPU pinning is correct:

   sh-4.4# pgrep systemd | while read i; do taskset -cp $i; done

   Example output

   pid 1's current affinity list: 0-3
   pid 938's current affinity list: 0-3
   pid 962's current affinity list: 0-3
   pid 1197's current affinity list: 0-3

Reduced platform management footprint

To reduce the overall management footprint of the platform, a MachineConfig custom resource (CR) is required that places all Kubernetes-specific mount points in a new namespace separate from the host operating system. The following base64-encoded example MachineConfig CR illustrates this configuration.

Recommended container mount namespace configuration (01-container-mount-ns-and-kubelet-conf-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: container-mount-namespace-and-kubelet-conf-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
      - contents:
          source: data:text/plain;charset=utf-8;base64,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
        mode: 493
        path: /usr/local/bin/extractExecStart
      - contents:
          source: data:text/plain;charset=utf-8;base64,IyEvYmluL2Jhc2gKbnNlbnRlciAtLW1vdW50PS9ydW4vY29udGFpbmVyLW1vdW50LW5hbWVzcGFjZS9tbnQgIiRAIgo=
        mode: 493
        path: /usr/local/bin/nsenterCmns
    systemd:
      units:
      - contents: |
          [Unit]
          Description=Manages a mount namespace that both kubelet and crio can use to share their container-specific mounts
          [Service]
          Type=oneshot
          RemainAfterExit=yes
          RuntimeDirectory=container-mount-namespace
          Environment=RUNTIME_DIRECTORY=%t/container-mount-namespace
          Environment=BIND_POINT=%t/container-mount-namespace/mnt
          ExecStartPre=bash -c "findmnt ${RUNTIME_DIRECTORY} || mount --make-unbindable --bind ${RUNTIME_DIRECTORY} ${RUNTIME_DIRECTORY}"
          ExecStartPre=touch ${BIND_POINT}
          ExecStart=unshare --mount=${BIND_POINT} --propagation slave mount --make-rshared /
          ExecStop=umount -R ${RUNTIME_DIRECTORY}
        name: container-mount-namespace.service
      - dropins:
        - contents: |
            [Unit]
            Wants=container-mount-namespace.service
            After=container-mount-namespace.service
            [Service]
            ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
            EnvironmentFile=-/%t/%N-execstart.env
            ExecStart=
            ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                ${ORIG_EXECSTART}"
          name: 90-container-mount-namespace.conf
        name: crio.service
      - dropins:
        - contents: |
            [Unit]
            Wants=container-mount-namespace.service
            After=container-mount-namespace.service
            [Service]
            ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
            EnvironmentFile=-/%t/%N-execstart.env
            ExecStart=
            ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                ${ORIG_EXECSTART} --housekeeping-interval=30s"
          name: 90-container-mount-namespace.conf
        - contents: |
            [Service]
            Environment="OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION=60s"
            Environment="OPENSHIFT_EVICTION_MONITORING_PERIOD_DURATION=30s"
          name: 30-kubelet-interval-tuning.conf
        name: kubelet.service

SCTP

Stream Control Transmission Protocol (SCTP) is a key protocol used in RAN applications. This MachineConfig object adds the SCTP kernel module to the node to enable this protocol.

Recommended SCTP configuration (03-sctp-machine-config-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: load-sctp-module-master
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8,sctp
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

Accelerated container startup

The following MachineConfig CR configures core OpenShift processes and containers to use all available CPU cores during system startup and shutdown. This accelerates the system recovery during initial boot and reboots.

Recommended accelerated container startup configuration (04-accelerated-container-startup-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 04-accelerated-container-startup-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
      - contents:
          source: data:text/plain;charset=utf-8;base64,#!/bin/bash
#
# Temporarily reset the core system processes's CPU affinity to be unrestricted to accelerate startup and shutdown
#
# The defaults below can be overridden via environment variables
#

# The default set of critical processes whose affinity should be temporarily unbound:
CRITICAL_PROCESSES=${CRITICAL_PROCESSES:-"crio kubelet NetworkManager conmon dbus"}

# Default wait time is 600s = 10m:
MAXIMUM_WAIT_TIME=${MAXIMUM_WAIT_TIME:-600}

# Default steady-state threshold = 2%
# Allowed values:
#  4  - absolute pod count (+/-)
#  4% - percent change (+/-)
#  -1 - disable the steady-state check
STEADY_STATE_THRESHOLD=${STEADY_STATE_THRESHOLD:-2%}

# Default steady-state window = 60s
# If the running pod count stays within the given threshold for this time
# period, return CPU utilization to normal before the maximum wait time has
# expires
STEADY_STATE_WINDOW=${STEADY_STATE_WINDOW:-60}

# Default steady-state allows any pod count to be "steady state"
# Increasing this will skip any steady-state checks until the count rises above
# this number to avoid false positives if there are some periods where the
# count doesn't increase but we know we can't be at steady-state yet.
STEADY_STATE_MINIMUM=${STEADY_STATE_MINIMUM:-0}

#######################################################

KUBELET_CPU_STATE=/var/lib/kubelet/cpu_manager_state
FULL_CPU_STATE=/sys/fs/cgroup/cpuset/cpuset.cpus
KUBELET_CONF=/etc/kubernetes/kubelet.conf
unrestrictedCpuset() {
  local cpus
  if [[ -e $KUBELET_CPU_STATE ]]; then
    cpus=$(jq -r '.defaultCpuSet' <$KUBELET_CPU_STATE)
    if [[ -n "${cpus}" && -e ${KUBELET_CONF} ]]; then
      reserved_cpus=$(jq -r '.reservedSystemCPUs' </etc/kubernetes/kubelet.conf)
      if [[ -n "${reserved_cpus}" ]]; then
        # Use taskset to merge the two cpusets
        cpus=$(taskset -c "${reserved_cpus},${cpus}" grep -i Cpus_allowed_list /proc/self/status | awk '{print $2}')
      fi
    fi
  fi
  if [[ -z $cpus ]]; then
    # fall back to using all cpus if the kubelet state is not configured yet
    [[ -e $FULL_CPU_STATE ]] || return 1
    cpus=$(<$FULL_CPU_STATE)
  fi
  echo $cpus
}

restrictedCpuset() {
  for arg in $(</proc/cmdline); do
    if [[ $arg =~ ^systemd.cpu_affinity= ]]; then
      echo ${arg#*=}
      return 0
    fi
  done
  return 1
}

resetAffinity() {
  local cpuset="$1"
  local failcount=0
  local successcount=0
  logger "Recovery: Setting CPU affinity for critical processes \"$CRITICAL_PROCESSES\" to $cpuset"
  for proc in $CRITICAL_PROCESSES; do
    local pids="$(pgrep $proc)"
    for pid in $pids; do
      local tasksetOutput
      tasksetOutput="$(taskset -apc "$cpuset" $pid 2>&1)"
      if [[ $? -ne 0 ]]; then
        echo "ERROR: $tasksetOutput"
        ((failcount++))
      else
        ((successcount++))
      fi
    done
  done

  logger "Recovery: Re-affined $successcount pids successfully"
  if [[ $failcount -gt 0 ]]; then
    logger "Recovery: Failed to re-affine $failcount processes"
    return 1
  fi
}

setUnrestricted() {
  logger "Recovery: Setting critical system processes to have unrestricted CPU access"
  resetAffinity "$(unrestrictedCpuset)"
}

setRestricted() {
  logger "Recovery: Resetting critical system processes back to normally restricted access"
  resetAffinity "$(restrictedCpuset)"
}

currentAffinity() {
  local pid="$1"
  taskset -pc $pid | awk -F': ' '{print $2}'
}

within() {
  local last=$1 current=$2 threshold=$3
  local delta=0 pchange
  delta=$(( current - last ))
  if [[ $current -eq $last ]]; then
    pchange=0
  elif [[ $last -eq 0 ]]; then
    pchange=1000000
  else
    pchange=$(( ( $delta * 100) / last ))
  fi
  echo -n "last:$last current:$current delta:$delta pchange:${pchange}%: "
  local absolute limit
  case $threshold in
    *%)
      absolute=${pchange##-} # absolute value
      limit=${threshold%%%}
      ;;
    *)
      absolute=${delta##-} # absolute value
      limit=$threshold
      ;;
  esac
  if [[ $absolute -le $limit ]]; then
    echo "within (+/-)$threshold"
    return 0
  else
    echo "outside (+/-)$threshold"
    return 1
  fi
}

steadystate() {
  local last=$1 current=$2
  if [[ $last -lt $STEADY_STATE_MINIMUM ]]; then
    echo "last:$last current:$current Waiting to reach $STEADY_STATE_MINIMUM before checking for steady-state"
    return 1
  fi
  within $last $current $STEADY_STATE_THRESHOLD
}

waitForReady() {
  logger "Recovery: Waiting ${MAXIMUM_WAIT_TIME}s for the initialization to complete"
  local lastSystemdCpuset="$(currentAffinity 1)"
  local lastDesiredCpuset="$(unrestrictedCpuset)"
  local t=0 s=10
  local lastCcount=0 ccount=0 steadyStateTime=0
  while [[ $t -lt $MAXIMUM_WAIT_TIME ]]; do
    sleep $s
    ((t += s))
    # Re-check the current affinity of systemd, in case some other process has changed it
    local systemdCpuset="$(currentAffinity 1)"
    # Re-check the unrestricted Cpuset, as the allowed set of unreserved cores may change as pods are assigned to cores
    local desiredCpuset="$(unrestrictedCpuset)"
    if [[ $systemdCpuset != $lastSystemdCpuset || $lastDesiredCpuset != $desiredCpuset ]]; then
      resetAffinity "$desiredCpuset"
      lastSystemdCpuset="$(currentAffinity 1)"
      lastDesiredCpuset="$desiredCpuset"
    fi

    # Detect steady-state pod count
    ccount=$(crictl ps | wc -l)
    if steadystate $lastCcount $ccount; then
      ((steadyStateTime += s))
      echo "Steady-state for ${steadyStateTime}s/${STEADY_STATE_WINDOW}s"
      if [[ $steadyStateTime -ge $STEADY_STATE_WINDOW ]]; then
        logger "Recovery: Steady-state (+/- $STEADY_STATE_THRESHOLD) for ${STEADY_STATE_WINDOW}s: Done"
        return 0
      fi
    else
      if [[ $steadyStateTime -gt 0 ]]; then
        echo "Resetting steady-state timer"
        steadyStateTime=0
      fi
    fi
    lastCcount=$ccount
  done
  logger "Recovery: Recovery Complete Timeout"
}

main() {
  if ! unrestrictedCpuset >&/dev/null; then
    logger "Recovery: No unrestricted Cpuset could be detected"
    return 1
  fi

  if ! restrictedCpuset >&/dev/null; then
    logger "Recovery: No restricted Cpuset has been configured.  We are already running unrestricted."
    return 0
  fi

  # Ensure we reset the CPU affinity when we exit this script for any reason
  # This way either after the timer expires or after the process is interrupted
  # via ^C or SIGTERM, we return things back to the way they should be.
  trap setRestricted EXIT

  logger "Recovery: Recovery Mode Starting"
  setUnrestricted
  waitForReady
}

if [[ "${BASH_SOURCE[0]}" = "${0}" ]]; then
  main "${@}"
  exit $?
fi

        mode: 493
        path: /usr/local/bin/accelerated-container-startup.sh
    systemd:
      units:
      - contents: |
          [Unit]
          Description=Unlocks more CPUs for critical system processes during container startup
          [Service]
          Type=simple
          ExecStart=/usr/local/bin/accelerated-container-startup.sh
          # Maximum wait time is 600s = 10m:
          Environment=MAXIMUM_WAIT_TIME=600
          # Steady-state threshold = 2%
          # Allowed values:
          #  4  - absolute pod count (+/-)
          #  4% - percent change (+/-)
          #  -1 - disable the steady-state check
          # Note: '%' must be escaped as '%%' in systemd unit files
          Environment=STEADY_STATE_THRESHOLD=2%%
          # Steady-state window = 120s
          # If the running pod count stays within the given threshold for this time
          # period, return CPU utilization to normal before the maximum wait time has
          # expires
          Environment=STEADY_STATE_WINDOW=120
          # Steady-state minimum = 40
          # Increasing this will skip any steady-state checks until the count rises above
          # this number to avoid false positives if there are some periods where the
          # count doesn't increase but we know we can't be at steady-state yet.
          Environment=STEADY_STATE_MINIMUM=40
          [Install]
          WantedBy=multi-user.target
        enabled: true
        name: accelerated-container-startup.service
      - contents: |
          [Unit]
          Description=Unlocks more CPUs for critical system processes during container shutdown
          DefaultDependencies=no
          [Service]
          Type=simple
          ExecStart=/usr/local/bin/accelerated-container-startup.sh
          # Maximum wait time is 600s = 10m:
          Environment=MAXIMUM_WAIT_TIME=600
          # Steady-state threshold
          # Allowed values:
          #  4  - absolute pod count (+/-)
          #  4% - percent change (+/-)
          #  -1 - disable the steady-state check
          # Note: '%' must be escaped as '%%' in systemd unit files
          Environment=STEADY_STATE_THRESHOLD=-1
          # Steady-state window = 60s
          # If the running pod count stays within the given threshold for this time
          # period, return CPU utilization to normal before the maximum wait time has
          # expires
          Environment=STEADY_STATE_WINDOW=60
          [Install]
          WantedBy=shutdown.target reboot.target halt.target
        enabled: true
        name: accelerated-container-shutdown.service

Setting rcu_normal

The following MachineConfig CR configures the system to set rcu_normal to 1 after the system has finished startup. This improves kernel latency for vDU applications.

Recommended configuration for disabling rcu_expedited after the node has finished startup in the 08-set-rcu-normal-master.yaml file

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 08-set-rcu-normal-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
      - contents:
          source: data:text/plain;charset=utf-8;base64,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
        mode: 493
        path: /usr/local/bin/set-rcu-normal.sh
    systemd:
      units:
      - contents: |
          [Unit]
          Description=Disable rcu_expedited after node has finished booting by setting rcu_normal to 1
          [Service]
          Type=simple
          ExecStart=/usr/local/bin/set-rcu-normal.sh
          # Maximum wait time is 600s = 10m:
          Environment=MAXIMUM_WAIT_TIME=600
          # Steady-state threshold = 2%
          # Allowed values:
          #  4  - absolute pod count (+/-)
          #  4% - percent change (+/-)
          #  -1 - disable the steady-state check
          # Note: '%' must be escaped as '%%' in systemd unit files
          Environment=STEADY_STATE_THRESHOLD=2%%
          # Steady-state window = 120s
          # If the running pod count stays within the given threshold for this time
          # period, return CPU utilization to normal before the maximum wait time has
          # expires
          Environment=STEADY_STATE_WINDOW=120
          # Steady-state minimum = 40
          # Increasing this will skip any steady-state checks until the count rises above
          # this number to avoid false positives if there are some periods where the
          # count doesn't increase but we know we can't be at steady-state yet.
          Environment=STEADY_STATE_MINIMUM=40
          [Install]
          WantedBy=multi-user.target
        enabled: true
        name: set-rcu-normal.service

Automatic kernel crash dumps with kdump

kdump is a Linux kernel feature that creates a kernel crash dump when the kernel crashes. kdump is enabled with the following MachineConfig CRs.

Recommended MachineConfig to remove ice driver (05-kdump-config-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 05-kdump-config-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
      - enabled: true
        name: kdump-remove-ice-module.service
        contents: |
          [Unit]
          Description=Remove ice module when doing kdump
          Before=kdump.service
          [Service]
          Type=oneshot
          RemainAfterExit=true
          ExecStart=/usr/local/bin/kdump-remove-ice-module.sh
          [Install]
          WantedBy=multi-user.target
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 448
          path: /usr/local/bin/kdump-remove-ice-module.sh

Recommended kdump configuration (06-kdump-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 06-kdump-enable-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
      - enabled: true
        name: kdump.service
  kernelArguments:
    - crashkernel=512M

Disable automatic CRI-O cache wipe

After an uncontrolled host shutdown or cluster reboot, CRI-O automatically deletes the entire CRI-O cache, causing all images to be pulled from the registry when the node reboots. This can result in unacceptably slow recovery times or recovery failures. To prevent this from happening in single-node OpenShift clusters that you install with GitOps ZTP, disable the CRI-O delete cache feature during cluster installation.

Recommended MachineConfig CR to disable CRI-O cache wipe on control plane nodes (99-crio-disable-wipe-master.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-crio-disable-wipe-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

Recommended MachineConfig CR to disable CRI-O cache wipe on worker nodes (99-crio-disable-wipe-worker.yaml)

# Automatically generated by extra-manifests-builder
# Do not make changes directly.
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-crio-disable-wipe-worker
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

Configuring crun as the default container runtime

The following ContainerRuntimeConfig custom resources (CRs) configure crun as the default OCI container runtime for control plane and worker nodes. The crun container runtime is fast and lightweight and has a low memory footprint.

Recommended ContainerRuntimeConfig CR for control plane nodes (enable-crun-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
 name: enable-crun-master
spec:
 machineConfigPoolSelector:
   matchLabels:
     pools.operator.machineconfiguration.openshift.io/master: ""
 containerRuntimeConfig:
   defaultRuntime: crun

Recommended ContainerRuntimeConfig CR for worker nodes (enable-crun-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
 name: enable-crun-worker
spec:
 machineConfigPoolSelector:
   matchLabels:
     pools.operator.machineconfiguration.openshift.io/worker: ""
 containerRuntimeConfig:
   defaultRuntime: crun

Recommended postinstallation cluster configurations

When the cluster installation is complete, the ZTP pipeline applies the following custom resources (CRs) that are required to run DU workloads.

Operator namespaces and Operator groups

Single-node OpenShift clusters that run DU workloads require the following OperatorGroup and Namespace custom resources (CRs):

• Local Storage Operator

• Logging Operator

• PTP Operator

• SR-IOV Network Operator

The following CRs are required:

Recommended Storage Operator Namespace and OperatorGroup configuration

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-local-storage
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: openshift-local-storage
  namespace: openshift-local-storage
spec:
  targetNamespaces:
  - openshift-local-storage

Recommended Cluster Logging Operator Namespace and OperatorGroup configuration

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-logging
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: cluster-logging
  namespace: openshift-logging
spec:
  targetNamespaces:
  - openshift-logging

Recommended PTP Operator Namespace and OperatorGroup configuration

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-ptp
  annotations:
    workload.openshift.io/allowed: management
  labels:
    openshift.io/cluster-monitoring: "true"
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: ptp-operators
  namespace: openshift-ptp
spec:
  targetNamespaces:
  - openshift-ptp

Recommended SR-IOV Operator Namespace and OperatorGroup configuration

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-sriov-network-operator
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: sriov-network-operators
  namespace: openshift-sriov-network-operator
spec:
  targetNamespaces:
  - openshift-sriov-network-operator

Operator subscriptions

Single-node OpenShift clusters that run DU workloads require the following Subscription CRs. The subscription provides the location to download the following Operators:

• Local Storage Operator

• Logging Operator

• PTP Operator

• SR-IOV Network Operator

For each Operator subscription, specify the channel to get the Operator from. The recommended channel is stable.

You can specify Manual or Automatic updates. In Automatic mode, the Operator automatically updates to the latest versions in the channel as they become available in the registry. In Manual mode, new Operator versions are installed only when they are explicitly approved.

Recommended Local Storage Operator subscription

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: local-storage-operator
  namespace: openshift-local-storage
spec:
  channel: "stable"
  name: local-storage-operator
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended SR-IOV Operator subscription

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sriov-network-operator-subscription
  namespace: openshift-sriov-network-operator
spec:
  channel: "stable"
  name: sriov-network-operator
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended PTP Operator subscription

---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: ptp-operator-subscription
  namespace: openshift-ptp
spec:
  channel: "stable"
  name: ptp-operator
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended Cluster Logging Operator subscription

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: cluster-logging
  namespace: openshift-logging
spec:
  channel: "stable"
  name: cluster-logging
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Cluster logging and log forwarding

Single-node OpenShift clusters that run DU workloads require logging and log forwarding for debugging. The following ClusterLogging and ClusterLogForwarder custom resources (CRs) are required.

Recommended cluster logging and log forwarding configuration

apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  name: instance
  namespace: openshift-logging
spec:
 managementState: "Managed"
 curation:
   type: "curator"
   curator:
     schedule: "30 3 * * *"
 collection:
   logs:
     type: "fluentd"
     fluentd: {}

Recommended log forwarding configuration

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
spec:
  outputs:
    - type: "kafka"
      name: kafka-open
      url: tcp://10.46.55.190:9092/test
  inputs:
    - name: infra-logs
      infrastructure: {}
  pipelines:
    - name: audit-logs
      inputRefs:
        - audit
      outputRefs:
        - kafka-open
    - name: infrastructure-logs
      inputRefs:
        - infrastructure
      outputRefs:
        - kafka-open

Set the spec.outputs.url field to the URL of the Kafka server where the logs are forwarded to.

Performance profile

Single-node OpenShift clusters that run DU workloads require a Node Tuning Operator performance profile to use real-time host capabilities and services.

The following example PerformanceProfile CR illustrates the required single-node OpenShift cluster configuration.

Recommended performance profile configuration

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: openshift-node-performance-profile
spec:
  additionalKernelArgs:
  - "rcupdate.rcu_normal_after_boot=0"
  - "efi=runtime"
  - "module_blacklist=irdma"
  cpu:
    isolated: 2-51,54-103
    reserved: 0-1,52-53
  hugepages:
    defaultHugepagesSize: 1G
    pages:
      - count: 32
        size: 1G
        node: 0
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/master: ""
  nodeSelector:
    node-role.kubernetes.io/master: ''
  numa:
    topologyPolicy: "restricted"
  realTimeKernel:
    enabled: true
  workloadHints:
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

PTP

Single-node OpenShift clusters use Precision Time Protocol (PTP) for network time synchronization. The following example PtpConfig CR illustrates the required PTP slave configuration.

Recommended PTP configuration

apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: slave
  namespace: openshift-ptp
spec:
  profile:
  - name: "slave"
    # The interface name is hardware-specific
    interface: ens5f0
    ptp4lOpts: "-2 -s"
    phc2sysOpts: "-a -r -n 24"
    ptpSchedulingPolicy: SCHED_FIFO
    ptpSchedulingPriority: 10
    ptpSettings:
      logReduce: "true"
    ptp4lConf: |
      [global]
      #
      # Default Data Set
      #
      twoStepFlag 1
      slaveOnly 0
      priority1 128
      priority2 128
      domainNumber 24
      #utc_offset 37
      clockClass 255
      clockAccuracy 0xFE
      offsetScaledLogVariance 0xFFFF
      free_running 0
      freq_est_interval 1
      dscp_event 0
      dscp_general 0
      dataset_comparison G.8275.x
      G.8275.defaultDS.localPriority 128
      #
      # Port Data Set
      #
      logAnnounceInterval -3
      logSyncInterval -4
      logMinDelayReqInterval -4
      logMinPdelayReqInterval -4
      announceReceiptTimeout 3
      syncReceiptTimeout 0
      delayAsymmetry 0
      fault_reset_interval 4
      neighborPropDelayThresh 20000000
      masterOnly 0
      G.8275.portDS.localPriority 128
      #
      # Run time options
      #
      assume_two_step 0
      logging_level 6
      path_trace_enabled 0
      follow_up_info 0
      hybrid_e2e 0
      inhibit_multicast_service 0
      net_sync_monitor 0
      tc_spanning_tree 0
      tx_timestamp_timeout 50
      unicast_listen 0
      unicast_master_table 0
      unicast_req_duration 3600
      use_syslog 1
      verbose 0
      summary_interval 0
      kernel_leap 1
      check_fup_sync 0
      #
      # Servo Options
      #
      pi_proportional_const 0.0
      pi_integral_const 0.0
      pi_proportional_scale 0.0
      pi_proportional_exponent -0.3
      pi_proportional_norm_max 0.7
      pi_integral_scale 0.0
      pi_integral_exponent 0.4
      pi_integral_norm_max 0.3
      step_threshold 2.0
      first_step_threshold 0.00002
      max_frequency 900000000
      clock_servo pi
      sanity_freq_limit 200000000
      ntpshm_segment 0
      #
      # Transport options
      #
      transportSpecific 0x0
      ptp_dst_mac 01:1B:19:00:00:00
      p2p_dst_mac 01:80:C2:00:00:0E
      udp_ttl 1
      udp6_scope 0x0E
      uds_address /var/run/ptp4l
      #
      # Default interface options
      #
      clock_type OC
      network_transport L2
      delay_mechanism E2E
      time_stamping hardware
      tsproc_mode filter
      delay_filter moving_median
      delay_filter_length 10
      egressLatency 0
      ingressLatency 0
      boundary_clock_jbod 0
      #
      # Clock description
      #
      productDescription ;;
      revisionData ;;
      manufacturerIdentity 00:00:00
      userDescription ;
      timeSource 0xA0
  recommend:
  - profile: "slave"
    priority: 4
    match:
    - nodeLabel: "node-role.kubernetes.io/master"

Extended Tuned profile

Single-node OpenShift clusters that run DU workloads require additional performance tuning configurations necessary for high-performance workloads. The following example Tuned CR extends the Tuned profile:

Recommended extended Tuned profile configuration

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: performance-patch
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
    - name: performance-patch
      data: |
        [main]
        summary=Configuration changes profile inherited from performance created tuned
        include=openshift-node-performance-openshift-node-performance-profile
        [sysctl]
        kernel.timer_migration=1
        [scheduler]
        group.ice-ptp=0:f:10:*:ice-ptp.*
        group.ice-gnss=0:f:10:*:ice-gnss.*
        [service]
        service.stalld=start,enable
        service.chronyd=stop,disable
  recommend:
    - machineConfigLabels:
        machineconfiguration.openshift.io/role: "master"
      priority: 19
      profile: performance-patch

SR-IOV

Single root I/O virtualization (SR-IOV) is commonly used to enable fronthaul and midhaul networks. The following YAML example configures SR-IOV for a single-node OpenShift cluster.

Recommended SriovOperatorConfig configuration

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
  namespace: openshift-sriov-network-operator
spec:
  configDaemonNodeSelector:
    "node-role.kubernetes.io/master": ""
  enableInjector: true
  enableOperatorWebhook: true

containers:
- name: my-sriov-workload-container
  resources:
    limits:
      openshift.io/<resource_name>:  “1”
    requests:
      openshift.io/<resource_name>:  “1”

Recommended SriovNetwork configuration

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: ""
  namespace: openshift-sriov-network-operator
spec:
  resourceName: "du_mh"
  networkNamespace:  openshift-sriov-network-operator
  vlan: "150"
  spoofChk: ""
  ipam: ""
  linkState: ""
  maxTxRate: ""
  minTxRate: ""
  vlanQoS: ""
  trust: ""
  capabilities: ""

Recommended SriovNetworkNodePolicy configuration

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetworkNodePolicy
metadata:
  name: $name
  namespace: openshift-sriov-network-operator
spec:
  # Attributes for Mellanox/Intel based NICs
  deviceType: netdevice/vfio-pci
  isRdma: true/false
  nicSelector:
    # The exact physical function name must match the hardware used
    pfNames: [ens7f0]
  nodeSelector:
    node-role.kubernetes.io/master: ""
  numVfs: 8
  priority: 10
  resourceName: du_mh

Console Operator

Use the cluster capabilities feature to prevent the Console Operator from being installed. When the node is centrally managed it is not needed. Removing the Operator provides additional space and capacity for application workloads.

To disable the Console Operator during the installation of the managed cluster, set the following in the spec.clusters.0.installConfigOverrides field of the SiteConfig custom resource (CR):

installConfigOverrides:  "{\"capabilities\":{\"baselineCapabilitySet\": \"None\" }}"

Alertmanager

Single-node OpenShift clusters that run DU workloads require reduced CPU resources consumed by the OKD monitoring components. The following ConfigMap custom resource (CR) disables Alertmanager.

Recommended cluster monitoring configuration (ReduceMonitoringFootprint.yaml)

apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
  annotations:
    ran.openshift.io/ztp-deploy-wave: "1"
data:
  config.yaml: |
    alertmanagerMain:
      enabled: false
    prometheusK8s:
       retention: 24h

LVM Storage

You can dynamically provision local storage on single-node OpenShift clusters with Logical volume manager storage (LVM Storage).

The following YAML example configures the storage of the node to be available to OKD applications.

Recommended LVMCluster configuration (StorageLVMCluster.yaml)

apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
  name: odf-lvmcluster
  namespace: openshift-storage
spec:
  storage:
    deviceClasses:
    - name: vg1
      deviceSelector:
        paths:
        - /usr/disk/by-path/pci-0000:11:00.0-nvme-1
      thinPoolConfig:
        name: thin-pool-1
        overprovisionRatio: 10
        sizePercent: 90

Network diagnostics

Single-node OpenShift clusters that run DU workloads require less inter-pod network connectivity checks to reduce the additional load created by these pods. The following custom resource (CR) disables these checks.

Recommended network diagnostics configuration (DisableSnoNetworkDiag.yaml)

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  disableNetworkDiagnostics: true

Additional resources

• Deploying far edge sites using ZTP