Redis + AOF + Distributed Storage: A Cautionary Benchmark

We put AOF persistence through 9 configurations across local SSD SAS and Longhorn. The results are definitive. When designing a caching layer for a production migration to bare metal Kubernetes, we faced a question that sounds simple but turned out to have an expensive answer: should Redis AOF persistence live on Longhorn distributed storage? The Redis documentation hints at the answer. But intuition and documentation are not the same as production data. So we ran redis-benchmark across nine configurations — varying storage backend, persistence settings, and dataset size — and measured the impact empirically. The results are unambiguous, and one number in particular should give any architect pause. Test Configuration All tests used the same parameters throughout: requests: 50,000 clients: 20 parallel payload: 180,000 bytes (~180 KB) pipeline: keep-alive=1 thread: single-threaded The 180 KB payload is intentional — it reflects realistic cache object sizes for the production workload bei