Field Notes

Field Notes

Notes on operating systems, networks and the small tools I keep writing for myself.

September 28, 2026

What TCP keepalive actually does

It is not a heartbeat for your application. A walk through the kernel timers.

August 14, 2026

A 40-line backup script I trust

rsync, hard links and one rule: test the restore.

July 2, 2026

Older posts

Thirty-one posts since 2021.