IdeaWell

Project ideas from Hacker News discussions.

DIY NAS: 2026 Edition

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

The three most prevalent themes in the Hacker News discussion are:

1. The Role and Necessity of RAM in ZFS-based NAS Performance

There is significant discussion about how much RAM a NAS, especially one running ZFS, truly needs. While some legacy advice suggests a high ratio (like 1GB per 1TB of storage), many users argue that for non-deduplicated, typical home use, much less memory (8GB or even less) is sufficient, contrasting it with the heavy memory needs when using features like deduplication. The primary benefit of high RAM is for ZFS's Adaptive Replacement Cache (ARC).

  • Supporting Quotes:
    • "ZFS uses a large amount of ram, i think the old rule of thumb was 1GB ram per 1TB of storage" - "mewse-hn"
    • "You can run it with much less. I don't recall the bare minimum but with a bit of tweaking 2GB should be plenty" - "magicalhippo"
    • "For normal use, 2GB of RAM for that setup would be fine. But more RAM is more readily available cache, so more is better. It is certainly not even close to a requirement." - "dwood_dev"

2. The Value and Debate Surrounding ECC Memory for ZFS

A strong secondary theme revolves around whether ECC (Error-Correcting Code) RAM is essential for ZFS builds. Advocates argue that for a filesystem focused on end-to-end data integrity like ZFS, protecting data against bit flips in memory (which ZFS writes checksums for) is crucial. Skeptics counter that this concern is often overblown for typical home use and that most modern filesystems and hardware already mitigate this risk sufficiently.

  • Supporting Quotes:
    • "That’s why ECC RAM is particularly important for ZFS - without it you risk undermining the filesystem’s end-to-end integrity. Other filesystems usually lack such guarantees." - "supermatt"
    • "I believe the default is that ZFS uses 50% of your RAM for caching" - "cm2187" (This ties into the debate over memory protection for cached data).
    • "ECC is good for every file system. ZFS doesn't NEED ECC, but if you are running ZFS because you care about file integrity, then you're likely to care about memory integrity too." - "abrookewood"

3. The Trend of DIY Over Pre-built NAS Solutions (and Hardware Sourcing)

The discussion frequently contrasts building a custom NAS—often using budget or used enterprise parts—against buying pre-packaged solutions like Synology. Users value the power, customization, and cost-effectiveness of DIY builds, even while acknowledging the trade-offs regarding power consumption, complexity, and the inherent reliability concerns (or lack thereof) when sourcing niche or used components.

  • Supporting Quotes:
    • "A single 1080ti for transcoding or odd jobs that need a little CUDA (like photo tagging). Runs ResNet50-class models easily enough. I also wondered about treating it as a single-node SLURM server." - "joshvm" (Illustrating custom capability).
    • "But for a rare occasional home usage nor 32Gb nor this monstrosity and complexity doesn't make sense - just buy some 1-2 bay Synology and forget about it." - "justsomehnguy"
    • "I've had an H3 for a few years and it runs amazing. Very low power usage, small footprint and great stability... Before that I had a full size NAS with an efficient Fujitsi motherboard... That required so much extra work for so little power efficiency gains vs the Odroid." - "unruby" (Highlighting power efficiency gains in modern low-power SOC solutions).

🚀 Project Ideas

RAMBench: ZFS Cache Utilization Stress Tester

Summary

  • A tool designed to help users determine the optimal RAM allocation for their ZFS-based NAS by programmatically simulating high-re-use read workloads and measuring the relative performance impact of ARC cache hits vs. misses.
  • Core Value Proposition: Turns the abstract ZFS RAM/cache discussion into actionable, measurable data for home lab users.

Details

Key Value
Target Audience DIY NAS builders using ZFS (TrueNAS, Proxmox setups) focused on workload efficiency vs. hardware cost.
Core Feature CLI utility that runs a controlled sequence of file reads against a large dataset on the ZFS pool, progressively limiting available free memory to force ARC eviction/re-caching, while timing the operations.
Tech Stack Go or Rust (for fast CLI execution), leveraging system calls to manage memory pressure or by direct interaction with ZFS tools (like zpool iostat or kernel interfaces if possible).
Difficulty Medium
Monetization Hobby

Notes

  • Why HN commenters would love it: Directly addresses the confusion around "how much RAM is enough" debated in the thread (e.g., "The ZFS will eat up as much RAM as you give it as it caches files in memory as accessed.").
  • Potential for discussion or practical utility: Users could share benchmark results across different hardware/use cases, fostering better community guidelines than the currently debated "1GB per 1TB" rule.

In-Wall NAS Form Factor Validator

Summary

  • A 3D model repository and configurator tool that helps users design or select truly slim NAS hardware capable of fitting into limited-depth communication/wall enclosures (solving the <3.5" height constraint).
  • Core Value Proposition: Provides verified build plans/component lists that fit restrictive physical spaces where conventional mini-ITX or SFF chassis fail.

Details

Key Value
Target Audience Users prioritizing extreme stealth/low-profile deployment (e.g., the person asking about the Legrand enclosure).
Core Feature Interactive 3D model viewer allowing users to slot in compatible low-profile motherboards (like N100/N355 SBCs or specialized 1U boards) and external drive enclosures to validate total height/depth before purchase.
Tech Stack Web application using Three.js or similar for 3D visualization; Python/Rust backend for catalog management.
Difficulty High
Monetization Hobby

Notes

  • Why HN commenters would love it: Directly targets a niche physical constraint mentioned when discussing consumer-grade cases versus enterprise 1U/thin builds. Solves the "I'd like to stash something away and forget about it" problem.
  • Potential for discussion or practical utility: Could generate standardized BOMs for tiny, low-power builds using SBCs like the Odroid H4's successors.

ECC-Aware Build Advisor (ECC-ABA)

Summary

  • A specialized configuration tool that filters and recommends motherboard/CPU combinations strictly based on verified In-Band ECC (IBECC) support, directly linking this capability to ZFS requirements discussed in the thread.
  • Core Value Proposition: Simplifies the search for cost-effective, non-server hardware that provides critical ZFS memory integrity assurances, bridging the gap between consumer ease and enterprise safety.

Details

Key Value
Target Audience ZFS users who value data integrity but want to avoid traditional, power-hungry, slow-booting server platforms (like those preferring Alder Lake-N/N-series platform builds).
Core Feature Dynamic filtering of publicly available hardware lists (via scraped data from manufacturers/review sites like CNX) to only show CPU/Mobo pairings confirmed to enable IBECC, along with associated RAM recommendations.
Tech Stack Python backend for scraping/data processing, lightweight Flask/Django interface.
Difficulty Medium
Monetization Hobby

Notes

  • Why HN commenters would love it: IBECC was brought up as a significant, under-discussed feature that avoids the "server board" downsides. This tool automates identifying those rare consumer/SBC parts that offer this critical feature mentioned by users like evanjrowley.
  • Potential for discussion or practical utility: Could become the definitive public reference for non-standard ECC implementations outside of traditional Xeon/EPYC setups.