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OS & Runtime

Processes, memory, containers — the ground programs stand on

01 ·OS & Runtime·FREE·13 min read Processes and Memory from Scratch — What Is the OS Actually Protecting? One app can crash without taking the machine down with it. Process isolation and virtual memory are what make that ordinary. Starting from a post-office-box analogy, this builds up paging, address translation, TLBs, page faults, swap and the OOM killer from zero — and ends with you able to read free and dmesg yourself. 02 ·OS & Runtime·★ MEMBER·12 min read Containers from Scratch — What namespaces and cgroups Actually Are A container is not a lightweight virtual machine — it is an ordinary process with its view restricted. We take it apart into namespaces (what you can see), cgroups (how much you may use), and images (stacked read-only layers), from the first analogy through overlayfs, cpu.max, and how to read exit code 137. 03 ·OS & Runtime·★ MEMBER·9 min read File Systems from Scratch — What Does "Saved" Actually Guarantee? If the power dies half a second after your editor says "Saved," is the file still there? Starting from a library card catalogue, this builds up blocks, inodes, directories, journaling and fsync from zero — and ends with why databases refuse to trust the file system, and which knobs turn a quiet setting into a production incident.