SaunaFS 5.0 (now Leil OS) Drops: SMR Storage, But Not Like You Remember
Big news: we’ve just released SaunaFS 5.0. Midsummer in Estonia means bonfires, saunas, and new beginnings – so what better time to drop a game-changer? SaunaFS 5.0 is here, and it’s not just another version bump. This release brings real, measurable speed to HM-SMR storage and a whole lot of polish under the hood.
Reads and Writes: SMR, But Actually Fast
Let’s get real about performance. With SaunaFS 5.0 (paired with the ATTO Technology, Inc. ATTO ExpressSAS H1280 HBA), sequential throughput is up across the board:
| Test | Before (MB/s) | After (MB/s) | % Improvement |
|---|---|---|---|
| Sequential Writes (peak) | 4611 – 4904 | 5797 | +18 – 26% |
| Sequential Reads (peak, std alg.) | 4731 – 4778 | 6041 | +27% |
| Sequential Reads (peak, exp. alg.) | 4731 – 4778 | 9508 | +100% |
- Sequential Writes: Up to 5797 MB/s, 18–26% faster than before.
- Sequential Reads: Standard read now at 6041 MB/s (+27%), and the new experimental algorithm rockets to 9508 MB/s – over double the previous best.
These are SMR numbers. Shingled drives are not just for cold storage – with the right software and hardware, SMR can absolutely fly.
What Changed Under the Hood?
SaunaFS 5.0 isn’t just about speed. Here’s what’s new and improved for both Leil and the open community:
- Chunk-Based Write Algorithm: Writes are now faster, more parallel, and more efficient. The number of write workers is down, but throughput is up.
- Optimized Reads: Smarter batching and chunkserver logic mean sequential reads are smoother and faster, especially on big files.
- Mount & Stats Improvements: Faster mounts, snappier filesystem stats, and more reliable operation.
- Cleaner Codebase: Bugs squashed, memory management tightened, and deprecated features removed for a leaner, meaner system.
- Better Hardware Support: Seamless mixing of SMR and CMR drives, variable capacity drives, drives of different vendors, no downtime for hardware refreshes.
- Energy Efficiency: With SMR’s power disable (Pin 3) and ICE management, idle drives go dark, slashing energy use without sacrificing performance.
Why This Matters?
- SMR Isn’t Just Dense – It’s Fast: These numbers put SMR in the same league as CMR for sequential workloads, but with much better density and energy profile.
- Real-World Ready: SaunaFS 5.0 is built for production, with features like erasure coding, instant snapshots, and seamless scaling.
- Greener Storage: More data, less power, and a smaller carbon footprint – what’s not to like?
The Bottom Line
SaunaFS 5.0 proves that SMR doesn’t have to be a compromise. With the right stack, you get density, speed, and sustainability – all in one package. If you’re still thinking “shingles = slow,” it’s time to take another look.
Ready to see what SaunaFS 5.0 (now Leil OS) can do for your data center or open-source deployment? Let’s talk about putting these numbers to work for you.
Author: Alexander Ragel
Alexander Ragel is the CEO of Leil, an Estonia-based storage infrastructure company building HDD-native software for the exabyte era. Leil is in active co-engineering partnership with Western Digital, validated across the WD, Seagate, and Toshiba drive ecosystems.