Using Disk Compression With Btrfs To Enhance Performance

[phoronix]

Phoronix: Using Disk Compression With Btrfs To Enhance Performance

Earlier this month we delivered benchmarks comparing the ZFS, EXT4, and Btrfs file-systems from both solid-state drives and hard drives. The EXT4 file-system was the clear winner in terms of the overall disk performance while Btrfs came in second followed by Sun's ZFS in FreeBSD 8.2. It was a surprise that in our most recent testing the EXT4 file-system turned around and did better than the next-generation Btrfs file-system, but it turns out that Btrfs regressed hard in Linux 2.6.35 as to be found in Ubuntu 10.10 and other soon-to-be-released distributions. However, regardless of where Btrfs is performing, its speed can be boosted by enabling its transparent zlib compression support.

http://www.phoronix.com/vr.php?view=15233

[RealNC]

"Using Disk Compression With Btrfs To Enhance Performance"? But in the article itself you then claim there's no performance gain?

Explain?

[nanonyme]

Maybe it was sarcasm?

[3vi1]

Maybe it was sarcasm?

Yes, it was really great sarcasm.

[RealNC]

Oh. It was very subtle then

[Tenzer]

What effect did compression have on the CPU usage?
The following benchmark with ZFS' compression algorithms, states that gzip compression was very CPU bound in regards to performance, compared to lzjb compression: http://don.blogs.smugmug.com/2008/10...ession-update/

I wonder why they've gone for gzip compression, instead of something lighter such as lzjb, when tests on ZFS show such difference when comparing the performance against the space saving.

[3vi1]

Oh. It was very subtle then

Not as subtle as mine.

[thefirstm]

"Using Disk Compression With Btrfs To Enhance Performance"

and ext4 wins most of the benchmarks... Pwned!

[brent]

They should have used lzo instead of gzip.

Anyway, the important thing, *again*, what does the test data of the benchmark programs look like? If it's only zeros, that's not a very fair or realistic benchmark, it'll be skewed in favor of compressed filesystems.

See the iozone benchmark, for example.

[blagishnessosity]

The Vertex 2's SandForce controller implements compression at the hardware level. Activating software compression will of course decrease performance.