Free egress is not free serving. R2 still bills every read, S3 does not bill origin transfer to CloudFront, and the variable that decides both bills is cache hit ratio. An evenhanded comparison of Cloudflare R2 vs Amazon S3 for media offloading, with the four levers that move the number and a decision procedure you can run against your own traffic.
Most AWS cost work goes wrong because it starts with the biggest line item, which is also the riskiest. Order the work by blast radius instead: free networking and storage fixes first, performance envelopes one workload at a time, and commitments last. Includes the commands to find the waste and the cuts that look harmless and are not.
High I/O wait is a symptom, not a diagnosis. It rises when nothing is wrong and stays flat when something is badly wrong, and it only sees one layer of the storage stack. This is how to read iowait and PSI correctly, then work through the five failure families that actually produce storage stalls: device saturation, memory pressure, synchronous writes, throttling, and latency that lives above the block layer entirely.
Docker's default logging driver writes container output to a JSON file with no size limit and no rotation. This is a practical guide to Docker log rotation: what the defaults actually do, why your daemon.json change did nothing, why deleting the log file did not free any disk, and how to choose between json-file, local, journald and shipping logs off the box.
A PersistentVolumeClaim sounds like paperwork. Delete one on a cluster with the default reclaim policy and the underlying disk goes with it. A short guide to the parts of Kubernetes storage that bite: reclaim policies, access modes, zone affinity and StatefulSets.
The top search result tells you to run docker system prune -a --volumes. It frees the space and deletes your database. Here is how to measure Docker disk usage properly, reclaim it from safest to most destructive, and fix the logs that Docker never reports on.