Nodes swap memory fix 2

[mburke5678]

The docs about enabling swap memory are incorrect that cgroup v2 clusters cannot use limited swap memory. It should be cgroup v1 cluster cannot use limited swap.

Also:

• Removes references to Unlimited Swap (removed in OCP 4.17/Kubernetes v 1.30)
• Replaces it with NoSwap (added in OCP 4.17/Kubernetes v 1.30)
• Re-organizes and re-writes some of the text for clarity and to tighten things up a bit.

See the current docs: Enabling swap memory use on nodes

4.17+

Preview: Allowing swap memory use on nodes:

• Slight re-write of title for clarity
• Added intro paragraph
• Moved one of the (ick) stacked admonitions to the end of the section, right before the prereqs
• Reworked the three paragraphs following the (ick) stacked admonitions
• Added new prereq bullet 2.
• Removed (former) prereq bullet 4 (after the NOTE), as it is the same as Step 3, I think, and should come after the procedure.
• Procedure Step 2, call-out two, reworded, added NoSwap.
• Procedure Step 3, reworded.

QE review:

• QE has approved this change.

Related to: #92409

[ocpdocs-previewbot]

🤖 Fri Apr 25 21:32:45 - Prow CI generated the docs preview:

https://92421--ocpdocs-pr.netlify.app/openshift-enterprise/latest/nodes/nodes/nodes-nodes-managing.html

[kannon92]

Suggested change

	. Enable swap memory on the nodesS by setting the `swapaccount=1` kernel argument and configure swap memory as needed.
	. Enable swap memory on the nodes by setting the `swapaccount=1` kernel argument and configure swap memory as needed.

[kannon92]

So I'm not entirely sure what this means.

It wouldn't be possible to boot openshift if failSwapOn is true.

Any thing on the node could use swap but kubelet would not start if swap is enabled on the node.

[mburke5678]

@kannon92 What I was getting at is that when you set failSwapOn: false, whether you set swapBehavior: NoSwap or swapBehavior: LimitedSwap, and non-OCP workloads can use swap.
That was how I read the Kubernetes docs you suggested. (They have a nice example in system daemons, that perhaps I could add.)

[asahay19]

/lgtm

[openshift-ci]

New changes are detected. LGTM label has been removed.

[openshift-ci]

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[GroceryBoyJr]

/label peer-review-in-progress
/remove-label peer-review-needed
/assign GroceryBoyJr

[GroceryBoyJr]

LGTM

[GroceryBoyJr]

/label peer-review-done
/remove-label peer-review-in-progress
/unassign GroceryBoyJr