https://vlp.this52.cn/ Engineering notes on Linux systems, storage, and networking. https://vlp.this52.cn/posts/systemd-journald-disk-budget.html https://vlp.this52.cn/posts/systemd-journald-disk-budget.html 2026-11-08 Practical journald size caps, retention windows, and verification commands for hosts with 10 GB root partitions. https://vlp.this52.cn/posts/sqlite-wal-checkpoint-latency.html https://vlp.this52.cn/posts/sqlite-wal-checkpoint-latency.html 2026-10-29 Why WAL files occasionally grow past expected limits under concurrent readers and how passive vs. truncate checkpoints behave. https://vlp.this52.cn/posts/tls13-handshake-alpn-notes.html https://vlp.this52.cn/posts/tls13-handshake-alpn-notes.html 2026-10-14 A concise look at 1-RTT TLS 1.3 negotiation, HTTP/2 ALPN selection, and common Nginx / HAProxy gotchas. https://vlp.this52.cn/posts/linux-tcp-bbr-pacing-small-vps.html https://vlp.this52.cn/posts/linux-tcp-bbr-pacing-small-vps.html 2026-09-27 Measuring real congestion control, queuing disciplines, and memory trade-offs before tuning sysctl values.