Deployment

CSM for Resiliency is installed as part of the Dell CSI driver installation. The drivers can be installed either by a helm chart or by the Dell CSI Operator. Currently, only Helm chart installation is supported.

For information on the PowerFlex CSI driver, see PowerFlex CSI Driver.

For information on the Unity CSI driver, see Unity CSI Driver.

Configure all the helm chart parameters described below before installing the drivers.

Helm Chart Installation

The drivers that support Helm chart installation allow CSM for Resiliency to be optionally installed by variables in the chart. There is a podmon block specified in the values.yaml file of the chart that will look similar to the text below by default:

# Podmon is an optional feature under development and tech preview.
# Enable this feature only after contact support for additional information
podmon:
  enabled: true
  image: dellemc/podmon:v1.0.0
  controller:
    args:
      - "--csisock=unix:/var/run/csi/csi.sock"
      - "--labelvalue=csi-vxflexos"
      - "--mode=controller"
      - "--driver-config-params=/vxflexos-config-params/driver-config-params.yaml"
  node:
    args:
      - "--csisock=unix:/var/lib/kubelet/plugins/vxflexos.emc.dell.com/csi_sock"
      - "--labelvalue=csi-vxflexos"
      - "--mode=node"
      - "--leaderelection=false"
      - "--driver-config-params=/vxflexos-config-params/driver-config-params.yaml"

To install CSM for Resiliency with the driver, the following changes are required:

  1. Enable CSM for Resiliency by changing the podmon.enabled boolean to true. This will enable both controller-podmon and node-podmon.
  2. Specify the podmon image to be used as podmon.image.
  3. Specify arguments to controller-podmon in the podmon.controller.args block. See “Podmon Arguments” below. Note that some arguments are required. Note that the arguments supplied to controller-podmon are different from those supplied to node-podmon.
  4. Specify arguments to node-podmon in the podmon.node.args block. See “Podmon Arguments” below. Note that some arguments are required. Note that the arguments supplied to controller-podmon are different from those supplied to node-podmon.

Podmon Arguments

Argument Required Description Applicability
enabled Required Boolean “true” enables CSM for Resiliency installation with the driver in a helm installation. top level
image Required Must be set to a repository where the podmon image can be pulled. controller & node
mode Required Must be set to “controller” for controller-podmon and “node” for node-podmon. controller & node
csisock Required This should be left as set in the helm template for the driver. For controller:
-csisock=unix:/var/run/csi/csi.sock
For node it will vary depending on the driver’s identity:
-csisock=unix:/var/lib/kubelet/plugins
/vxflexos.emc.dell.com/csi_sock
controller & node
leaderelection Required Boolean value that should be set true for controller and false for node. The default value is true. controller & node
skipArrayConnectionValidation Optional Boolean value that if set to true will cause controllerPodCleanup to skip the validation that no I/O is ongoing before cleaning up the pod. controller
labelKey Optional String value that sets the label key used to denote pods to be monitored by CSM for Resiliency. It will make life easier if this key is the same for all driver types, and drivers are differentiated by different labelValues (see below). If the label keys are the same across all drivers you can do kubectl get pods -A -l labelKey to find all the CSM for Resiliency protected pods. labelKey defaults to “podmon.dellemc.com/driver”. controller & node
labelValue Required String that sets the value that denotes pods to be monitored by CSM for Resiliency. This must be specific for each driver. Defaults to “csi-vxflexos” for CSI Driver for Dell EMC PowerFlex and “csi-unity” for CSI Driver for Dell EMC Unity controller & node
arrayConnectivityPollRate Optional The minimum polling rate in seconds to determine if the array has connectivity to a node. Should not be set to less than 5 seconds. See the specific section for each array type for additional guidance. controller
arrayConnectivityConnectionLossThreshold Optional Gives the number of failed connection polls that will be deemed to indicate array connectivity loss. Should not be set to less than 3. See the specific section for each array type for additional guidance. controller
driver-config-params Required String that set the path to a file containing configuration parameter(for instance, Log levels) for a driver. controller & node

PowerFlex Specific Recommendations

PowerFlex supports a very robust array connection validation mechanism that can detect changes in connectivity in about two seconds and can detect whether I/O has occurred over a five-second sample. For that reason it is recommended to set “skipArrayConnectionValidation=false” (which is the default) and to set “arrayConnectivityPollRate=5” (5 seconds) and “arrayConnectivityConnectionLossThreshold=3” to 3 or more.

Here is a typical installation used for testing:

podmon:
  image: dellemc/podmon
  enabled: true
  controller:
    args:
      - "-csisock=unix:/var/run/csi/csi.sock"
      - "-labelvalue=csi-vxflexos"
      - "-mode=controller"
      - "-arrayConnectivityPollRate=5"
      - "-arrayConnectivityConnectionLossThreshold=3"
      - "--driver-config-params=/vxflexos-config-params/driver-config-params.yaml"
  node:
    args:
      - "-csisock=unix:/var/lib/kubelet/plugins/vxflexos.emc.dell.com/csi_sock"
      - "-labelvalue=csi-vxflexos"
      - "-mode=node"
      - "-leaderelection=false"
      - "--driver-config-params=/vxflexos-config-params/driver-config-params.yaml"

Unity Specific Recommendations

Here is a typical installation used for testing:

podmon:
   image: dellemc/podmon
   enabled: true
   controller:
     args:
       - "-csisock=unix:/var/run/csi/csi.sock"
       - "-labelvalue=csi-unity"
       - "-driverPath=csi-unity.dellemc.com"
       - "-mode=controller"
       - "--driver-config-params=/unity-config/driver-config-params.yaml"
   node:
     args:
       - "-csisock=unix:/var/lib/kubelet/plugins/unity.emc.dell.com/csi_sock"
       - "-labelvalue=csi-unity"
       - "-driverPath=csi-unity.dellemc.com"
       - "-mode=node"
       - "-leaderelection=false"
       - "--driver-config-params=/unity-config/driver-config-params.yaml"

Dynamic parameters

CSM for Resiliency has configuration parameters that can be updated dynamically, such as the logging level and format. This can be done by editing the DellEMC CSI Driver’s parameters ConfigMap. The ConfigMap can be queried using kubectl. For example, the DellEMC Powerflex CSI Driver ConfigMaps can be found using the following command: kubectl get -n vxflexos configmap. The ConfigMap to edit will have this pattern: -config-params (e.g., vxflexos-config-params).

To update or add parameters, you can use the kubectl edit command. For example, kubectl edit -n vxflexos configmap vxflexos-config-params.

This is a list of parameters that can be adjusted for CSM for Resiliency:

Parameter Type Default Description
PODMON_CONTROLLER_LOG_FORMAT String “text” Logging format output for the controller podmon sidecar. Should be “text” or “json”
PODMON_CONTROLLER_LOG_LEVEL String “debug” Logging level for the controller podmon sidecar. Standard values: ‘info’, ‘error’, ‘warning’, ‘debug’, ‘trace’
PODMON_NODE_LOG_FORMAT String “text” Logging format output for the node podmon sidecar. Should be “text” or “json”
PODMON_NODE_LOG_LEVEL String “debug” Logging level for the node podmon sidecar. Standard values: ‘info’, ‘error’, ‘warning’, ‘debug’, ‘trace’
PODMON_ARRAY_CONNECTIVITY_POLL_RATE Integer (>0) 15 An interval in seconds to poll the underlying array
PODMON_ARRAY_CONNECTIVITY_CONNECTION_LOSS_THRESHOLD Integer (>0) 3 A value representing the number of failed connection poll intervals before marking the array connectivity as lost
PODMON_SKIP_ARRAY_CONNECTION_VALIDATION Boolean false Flag to disable the array connectivity check

Here is an example of the parameters:

    PODMON_CONTROLLER_LOG_FORMAT: "text"
    PODMON_CONTROLLER_LOG_LEVEL: "info"
    PODMON_NODE_LOG_FORMAT: "text"
    PODMON_NODE_LOG_LEVEL: "info"
    PODMON_ARRAY_CONNECTIVITY_POLL_RATE: 20
    PODMON_ARRAY_CONNECTIVITY_CONNECTION_LOSS_THRESHOLD: 2
    PODMON_SKIP_ARRAY_CONNECTION_VALIDATION: true