OSDOCS 17429 AutoSizingReserved is enabled by default

modules/nodes-nodes-resources-configuring-setting.adoc

@@ -6,14 +6,16 @@
 [id="nodes-nodes-resources-configuring-setting_{context}"]
 = Manually allocating resources for nodes
 
-{product-title} supports the CPU and memory resource types for allocation. The `ephemeral-resource` resource type is also supported. For the `cpu` type, you specify the resource quantity in units of cores, such as `200m`, `0.5`, or `1`. For `memory` and `ephemeral-storage`, you specify the resource quantity in units of bytes, such as `200Ki`, `50Mi`, or `5Gi`. By default, the `system-reserved` CPU is `500m` and `system-reserved` memory is `1Gi`.
+[role="_abstract"]
+As an administrator, you can manually set `system-reserved` CPU and memory resources for your nodes. Setting these values ensures that your cluster is running efficiently and prevents node failure due to resource starvation of system components.
 
-As an administrator, you can set these values by using a kubelet config custom resource (CR) through a set of `<resource_type>=<resource_quantity>` pairs
-(e.g., `cpu=200m,memory=512Mi`).
+By default, {product-title} uses a script on each node to automatically determine the optimal `system-reserved` CPU and memory resources for nodes associated with a specific machine config pool and update the nodes with those values. {product-title} supports the CPU and memory resource types for allocation.
+
+However, you can manually set these values by using a `KubeletConfig`  custom resource (CR) through a set of `<resource_type>=<resource_quantity>` pairs (e.g., `cpu=200m,memory=512Mi`). For the `cpu` type, you specify the resource quantity in units of cores, such as `200m`, `0.5`, or `1`. For `memory` and `ephemeral-storage`, you specify the resource quantity in units of bytes, such as `200Ki`, `50Mi`, or `5Gi`. By default, the `system-reserved` CPU is `500m` and `system-reserved` memory is `1Gi`. Also, use the `autoSizingReserved: false` parameter to override the default {product-title} behavior of automatically setting the `systemReserved` values.
 
 [IMPORTANT]
 ====
-You must use a kubelet config CR to manually set resource values. You cannot use a machine config CR.
+You must use a `KubeletConfig` CR to manually set resource values. You cannot use a machine config CR.
 ====
 
 For details on the recommended `system-reserved` values, refer to the link:https://access.redhat.com/solutions/5843241[recommended system-reserved values].
@@ -70,22 +72,53 @@ kind: KubeletConfig
 metadata:
   name: set-allocatable <1>
 spec:
+  autoSizingReserved: false <2>
   machineConfigPoolSelector:
     matchLabels:
-      pools.operator.machineconfiguration.openshift.io/worker: "" <2>
+      pools.operator.machineconfiguration.openshift.io/worker: "" <3>
   kubeletConfig:
-    systemReserved: <3>
+    systemReserved: <4>
       cpu: 1000m
-      memory: 1Gi
+      memory: 4Gi
+      ephemeral-storage: 50Mi
 #...
 ----
 <1> Assign a name to CR.
-<2> Specify the label from the machine config pool.
-<3> Specify the resources to reserve for the node components and system components.
+<2> Specify `false` to override the default {product-title} behavior of automatically setting the `systemReserved` values.
+<3> Specify the label from the machine config pool.
+<4> Specify the resources to reserve for the node components and system components.
 
 . Run the following command to create the CR:
 +
 [source,terminal]
 ----
 $ oc create -f <file_name>.yaml
 ----
+
+.Verification
+
+. Log in to a node you configured by entering the following command:
++
+[source,terminal]
+----
+$ oc debug node/<node_name>
+----
+
+. Set `/host` as the root directory within the debug shell:
++
+[source,terminal]
+----
+# chroot /host
+----
+
+. View the `/etc/node-sizing.env` file:
++
+.Example output
+[source,terminal]
+----
+SYSTEM_RESERVED_MEMORY=4Gi
+SYSTEM_RESERVED_CPU=1000m
+SYSTEM_RESERVED_ES=50Mi
+----
++
+The kubelet uses the `system-reserved` values in the `/etc/node-sizing.env` file.

nodes/nodes/nodes-nodes-resources-configuring.adoc

@@ -6,7 +6,7 @@ include::_attributes/common-attributes.adoc[]
 
 toc::[]
 
-To provide more reliable scheduling and minimize node resource overcommitment, reserve a portion of the CPU and memory resources for use by the underlying node components, such as `kubelet` and `kube-proxy`, and the remaining system components, such as `sshd` and `NetworkManager`. By specifying the resources to reserve, you provide the scheduler with more information about the remaining CPU and memory resources that a node has available for use by pods. You can allow {product-title} to xref:../../nodes/nodes/nodes-nodes-resources-configuring.adoc#nodes-nodes-resources-configuring-auto_nodes-nodes-resources-configuring[automatically determine the optimal `system-reserved` CPU and memory resources] for your nodes or you can xref:../../nodes/nodes/nodes-nodes-resources-configuring.adoc#nodes-nodes-resources-configuring-setting_nodes-nodes-resources-configuring[manually determine and set the best resources] for your nodes.
+To provide more reliable scheduling and minimize node resource overcommitment, reserve a portion of the CPU and memory resources for use by the underlying node components, such as `kubelet` and `kube-proxy`, and the remaining system components, such as `sshd` and `NetworkManager`. By specifying the resources to reserve, you provide the scheduler with more information about the remaining CPU and memory resources that a node has available for use by pods. By default, {product-title} automatically determines the optimal `system-reserved` CPU and memory resources for your nodes or you can xref:../../nodes/nodes/nodes-nodes-resources-configuring.adoc#nodes-nodes-resources-configuring-setting_nodes-nodes-resources-configuring[manually determine and set the best resources] for your nodes.
 
 [IMPORTANT]
 ====
@@ -30,8 +30,6 @@ include::modules/sd-understanding-process-id-limits.adoc[leveloffset=+1]
 
 include::modules/risks-setting-higher-process-id-limits.adoc[leveloffset=+2]
 
-include::modules/nodes-nodes-resources-configuring-auto.adoc[leveloffset=+1]
-
 include::modules/nodes-nodes-resources-configuring-setting.adoc[leveloffset=+1]
 
 ////