Measuring the WAL vs DB Performance Gap on Ceph USB OSDs
Nine of my fifteen Ceph OSDs use WAL-only acceleration while six use DB. I set out to measure the performance gap and discovered the real story isn't WAL vs DB — it's the USB 3.0 hardware ceiling that dominates everything. The matched-hardware comparison shows DB is 5-15% faster on reads, not the 32% that naive cross-node testing suggested.
Linux Disk I/O Performance in the Homelab
Quick disk I/O benchmarks comparing eMMC and USB3 storage on Dell Wyse 3040s — understanding the performance characteristics of your storage tier before making capacity decisions.