Sysbench file tests

Benchmark profile:
- sequential test: 1 thread / 16 files 64 MB each / 2 MB block size
- random test: 1 thread / 16 files 64 MB each / 4 KB block size

Its now the turn of another synthetic benchmark: sysbench. It enable us to measure filesystem performance with sequential and random patterns and with normal (cached) or direct (not-cached) operations.

In sequential tests all filesytems behave more or less the same: this is expected, as these values depend primarily on the disk hardware subsystem. However, we can see that with synchronized writes (using fsync) BTRFS is somewhat slower then EXT3/4 and XFS.

Random I/O sysbench results always puzzled me a bit: it is clearly impossible to obtain over 13 MB/s with a mechanical disk and a truly randomic pattern. Anyway, we must score a point for XFS and BTRFS random read performance. Even their (much more realistic) random write speed is higher then EXT3 and EXT4.

Let see something about direct I/O performances. Sequential first...

… and then random:

If in the sequential direct I/O benchmark we don't see many differences relative to normal, cached I/O, in the random direct I/O test we see some variance. In detail, BTRFS is the fastest when reading, while XFS is the write champion.