Create an SVG histogram that shows Ceph OSD utilization statistics:
A well balanced Ceph cluster shows a narrow spike, while an imbalanced one shows a wide gauss curve. Added OSDs start from the left (0% utilization) and slowly merge into the main curve as the system balances.
Thanks to Tom Byrne for the graph idea. See his great presentation at https://www.youtube.com/watch?v=niFNZN5EKvE
Usage:
python3 -m venv _venv && _venv/bin/pip install -r requirements.txt
ceph osd df -f json | _venv/bin/python osd-usage-histogram.py > output.svg
In addition to the visualizer, this also contains a balance planner that suggest which OSDs to swap to improve the overall balance.
Run suggest-swaps.py to generate a plan.
Released under the MIT License (c) 2021-2024 by Jarno Elonen