Phoronix: Benchmarks Of The Btrfs Space Cache Option
In early November we delivered benchmarks of EXT4 vs. Btrfs on an early Linux 2.6.37 kernel as our latest round of tests comparing these two leading Linux file-systems. There were some changes in the Linux disk performance with these file-systems using the latest Linux kernel code, but overall it was not too interesting. However, as the Linux 2.6.37 kernel does introduce a new mount option for Btrfs, the space_cache option, we decided to explore its performance in today's article.
I don't know what kind of data the benchmarks use, but I'd like to see how btrfs performs when dealing with movies, audio or other already compressed data or mixed sets of data.
Benchmarks are fine but we are not all using just databases and as FireBurn suggests, it would be nice to see how a filesystem performs after having data written it enough to fill the partition 2x or 3x.
Could you compare the results with same configurations but a magnetic hard disk instead of ssd?
In this test is used OCZ 64GB Agility EX SSD. I believe it uses older Indilinx controller. The new Agility II uses SandForce SF-1200 controller. By default SF-1200 compresses the data before its written to the flash memory. So during the test suggested by ChrisXY I would love to see inclusion of SandForce based SSD. It will demonstrate how effective the compression option is when compression is done by SSD's controller.
My only problem with btrfs is the lack of a fsck tool that actually corrects errors, otherwise btrfs was working great until something went wrong and I couldn't correct errors in it. However, does space_cache deal with the huge about of "wasted space" that a btrfs system has?