IdeaWell

Project ideas from Hacker News discussions.

Stop making swap partitions–use swap files instead

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Theme 1 – Convenience and ease of setup
Many commenters point out that swap files are simpler to create and manage, especially when full‑disk encryption is involved.

“Swap files are also much easier to set up than partitions if you're using full disk encryption.” – mdspan

Theme 2 – Reliability and fragility concerns
Several users warn that swap files can be problematic for hibernation, may suffer from fragmentation, and are often allocated statically rather than being resized dynamically.

“Swap files are very fragile if you are using hibernation.” – demomode
“Linux distros that do use swap files do so statically. It doesn't handle dynamically growing and shrinking it …” – charcircuit

Theme 3 – Performance impact tied to disk layout and fragmentation
Performance considerations arise on HDDs or older filesystems; placement on the disk and fragmentation matter significantly.

“In practice, there’s a potentially tremendous impact if you’re using a spinning metal disk … sectors at the ‘beginning’ of the disk … are read/written way faster …” – WalterGR
“… there can be a performance impact if the filesystem is old … as long as the swap file isn’t fragmented there’s no impact.” – dwedge

🚀 Project Ideas

Generating project ideas…

DynamicSwapManager

Summary

  • Daemon that automatically grows/shrinks the swap file based on real‑time memory pressure while keeping it unfragmented.
  • Core value: eliminates manual swap tuning and prevents performance loss on encrypted or spinning disks.

Details

Key Value
Target Audience Linux sysadmins, laptop users with full‑disk encryption
Core Feature Adaptive swap file size + defragmentation safeguard
Tech Stack Rust (or C), systemd service, eBPF for memory pressure, fallocate/posix_fadvise for fragmentation control
Difficulty Medium
Monetization Hobby

Notes

  • HN commenters noted static swap files don’t handle dynamic growth (charcircuit) and fragmentation hurts performance (dwedge, WalterGR). This tool addresses both.
  • Could generate lively discussion on swap policies and be immediately useful for laptops/servers using FDE.

SwapPlacementAnalyzer

Summary

  • Scans a filesystem to locate swap‑file fragmentation and recommends optimal placement (e.g., outer tracks on HDDs) for maximum throughput.
  • Core value: gives actionable advice to avoid the slow‑end‑of‑disk penalty highlighted by WalterGR.

Details

Key Value
Target Audience Performance‑tuned desktop/server admins, hardware enthusiasts
Core Feature Fragmentation mapping + placement recommendation engine
Tech Stack Python, libext2fs / libblkid, optional C extension for low‑level disk layout
Difficulty Low
Monetization Hobby

Notes

  • WalterGR pointed out that sectors at the outer edge are faster and that long‑used filesystems often place free space at the slow end; this tool directly mitigates that.
  • Provides concrete, shareable results that would spark HN benchmarks and tuning threads.

EncryptedSwapWizard

Summary

  • Interactive CLI/GUI wizard that creates a swap file or partition inside LUKS/LVM, configures resume offsets for hibernation, and sets up proper crypttab/fstab entries.
  • Core value: simplifies the error‑prone setup of encrypted swap with hibernation support, addressing demomode’s concerns.

Details

Key Value
Target Audience Linux users deploying FDE laptops or servers who need hibernation
Core Feature Step‑by‑step encrypted swap creation with hibernation readiness
Tech Stack Go (or Bash + dialog), libcurl for docs, integration with cryptsetup/lvm2
Difficulty Medium
Monetization Hobby

Notes

  • demomode warned swap files are fragile with hibernation under FDE and recommended LVM‑over‑LUKS; this wizard automates that preferred setup.
  • Would likely be welcomed on HN as a practical guide and could reduce misconfiguration posts about swap/hibernation failures.

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