OSDOCS-30986 Update garbage collection with eviction conditions

Author: mburke5678

modules/nodes-nodes-garbage-collection-configuring.adoc

@@ -16,12 +16,10 @@ As an administrator, you can configure how {product-title} performs garbage coll
 
 You can configure any combination of the following:
 
-* Soft eviction for containers
+* Soft eviction for containers 
 * Hard eviction for containers
 * Eviction for images
 
-For the soft container eviction you can also configure a grace period before the eviction.
-
 .Prerequisites
 
 . Obtain the label associated with the static `MachineConfigPool` CRD for the type of node you want to configure.

modules/nodes-nodes-garbage-collection-containers.adoc

@@ -15,6 +15,24 @@ When eviction thresholds are set for garbage collection, the node tries to keep
 
 * *eviction-hard* - A hard eviction threshold has no grace period, and if observed, {product-title} takes immediate action.
 
+The following table lists the eviction thresholds:
+
+.Variables for configuring container garbage collection
+|===
+| Node condition | Eviction signal | Description
+
+| MemoryPressure 
+| `memory.available` 
+| The available memory on the node.
+
+| DiskPressure 
+a| * `nodefs.available`
+  * `nodefs.inodesFree`
+  * `imagefs.available`
+  * `imagefs.inodesFree`
+| The available disk space or inodes on the node root file system, `nodefs`, or image file system, `imagefs`.
+|===
+
 If a node is oscillating above and below a soft eviction threshold, but not exceeding its associated grace period, the corresponding node would constantly oscillate between `true` and `false`. As a consequence, the scheduler could make poor scheduling decisions.
 
 To protect against this oscillation, use the `eviction-pressure-transition-period` flag to control how long {product-title} must wait before transitioning out of a pressure condition. {product-title} will not set an eviction threshold as being met for the specified pressure condition for the period specified before toggling the condition back to false.