ZFS Raid-Z3 Performance with Zstandard (ZSTD) - Part 4 - Conclusion

Continuation of ZFS Raid-Z3 Performance with Zstandard (ZSTD) - Part 3 - Compressible Data Benchmarks

 

I started benchmarking this setup to get a feeling of the performance expectations and pitfalls of ZFS, Raid-Z, L2ARC and SLOG. This was especially interesting with different volblocksize settings

It started as few innocent benchmarks and it grew into what you have seen in the previous parts. But it grew more than I would have liked.

* A basic conclusion is that there is not one setup which is the best solution.

* volblocksize of 8k should probably be avoided for most normal usage, independent of if the application is heavy on using 8k io.

* volblocksize seems to have very little effect if used on a system without L2ARC. The L2ARC likes to have it as small as possible for small io sizes.

* volblocksize has little effect on writes. For this setup 32k was best regardless of if SLOG was used or not.

* L2ARC has some effect, but perhaps a SATA SSD improves performance but seems to be false economy. It makes more sense to invest on more memory.

* SLOG seems to have significant impact. I had trouble finding non-SATA SSD which had PLP support. But even SATA SSD doubled random write performance on this system.