[docs-scanner] Runtime metrics documentation incomplete for cgroup v2

[docker-agent]

File: content/manuals/engine/containers/runmetrics.md

Issue

The documentation explicitly acknowledges it's incomplete for cgroup v2:

Note

This section isn't yet updated for cgroup v2.
For further information about cgroup v2, refer to the kernel documentation.

This note appears in the "Metrics from cgroups: memory, CPU, block I/O" section, which then proceeds to document cgroup v1 metrics in detail.

Why this matters

Cgroup v2 has been the default on major Linux distributions since 2020-2021:

• Fedora (since 31, released 2019)
• Debian GNU/Linux (since 11, released 2021)
• Ubuntu (since 21.10, released 2021)

The documentation acknowledges cgroup v2 exists and even documents how to switch between versions, but then provides detailed metrics documentation only for cgroup v1. Users on modern systems following this documentation will find that the file paths and metric formats don't match what they see on their systems. The note essentially says "this documentation is incomplete" but doesn't provide the complete information.

Suggested fix

Either:

1. Update the metrics section to document both cgroup v1 and v2 formats side-by-side, or
2. Provide separate sections for v1 and v2 metrics with clear headings, or
3. If documenting v2 metrics is not feasible, make the limitation more prominent (move it to the top of the page) and provide more specific guidance on where users can find v2 metric information beyond just linking to kernel docs.

The current approach of documenting only v1 with a small note about v2 being unsupported creates a significant gap for users on modern systems.

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Found by nightly documentation quality scanner