GoKawiilNixOS trimmed to run stably on 512MB RAM via config changes
A NixOS user documented a multi-day effort to reduce the operating system's memory footprint, getting it to idle at roughly 96MB and complete a full rebuild within 512MB of RAM without triggering out-of-memory kills. By comparison, a stock NixOS deployment with cloud-init used 288MB at idle and needed up to 896MB to rebuild, previously causing OOM kills at 768MB on constrained setups. The changes included disabling kernel memory allocation profiling and reducing loaded kernel modules from 89 to 54.
GoKawiil's interpretation of the reporting above, not reported fact.
Lowering NixOS's baseline resource requirements could make it more viable for cheap, low-memory VPS instances where every megabyte of RAM affects hosting cost, according to the author's own testing notes. The author distinguishes this effort from disk-space-minimization guides, suggesting memory tuning and storage tuning are separate concerns that could be combined but carry different trade-offs for default user expectations. Because the work was done informally without a blog-writing intent from the start, some of the specific tweaks may be incompletely documented.
- NixOS idle memory usage was reduced from about 288MB to roughly 96MB.
- A full rebuild including a kernel switch completed within 512MB RAM with a 371MB peak and no OOM kill.
- Kernel memory allocation profiling (mem_profiling) was disabled to save about 6MB of overhead.
Raspberry Pi 4 Model B (4GB) — If you're experimenting with squeezing NixOS down to a bare-minimum footprint, a Raspberry Pi 4 is the perfect low-power playground to test those tweaks on real constrained hardware. Its modest RAM and ARM architecture make it an ideal testbed for minimal NixOS builds outside of a VPS. Great for tinkerers who want to see how low they can really go.
See Raspberry Pi 4 Model B (4GB) on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: lowendspirit.com, 2026-11-01
Published there as: “Shrinking NixOS RAM footprint and resource requirements to the bare minimum”
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