I tried twice with the same options, on linux 3.8.21 and 4.2.1, and write performance is very different on these kernels (I rebooted every time in between).
On 3.18.21, the source raid is hardly able to keep up with the write speed, f2fs basically writes at more or less full disk speed, for extended periods of time. As mentiopned earlier, average write speed was 103MB/s over the whole 2.1TB, with f2fs being idle a lot of that time, so actual write speed would be higher. On 4.2.1, same mkfs+mount options, performance is 5-10 times less, i.e. <<100MB/s (and more like 20MB/s for extendesd stretches): http://ue.tst.eu/43a8f7ae96ac770dc45ac8f1e3b0c479.txt (see the dsk/sde columns) First there is a "good" stretch with >100MB/s, then it starts to degrade. Another difference is the frequent read activity, which is mostly absent on 3.18.21. The log starts after only 20GB had been written. Here is the status output at 25GB: http://ue.tst.eu/734f7883107ee4dabff77602db92310b.txt Any idea why 4.2.1 performs so much worse than 3.8.21? (Note, if that is the difference between "filesystem works" (4.2.1?) and "filesystem doesn't work" (3.18.21) then that might be it - still, that would mean f2fs performs worse than traditional filesystems on these disks). -- The choice of a Deliantra, the free code+content MORPG -----==- _GNU_ http://www.deliantra.net ----==-- _ generation ---==---(_)__ __ ____ __ Marc Lehmann --==---/ / _ \/ // /\ \/ / schm...@schmorp.de -=====/_/_//_/\_,_/ /_/\_\ ------------------------------------------------------------------------------ Monitor Your Dynamic Infrastructure at Any Scale With Datadog! Get real-time metrics from all of your servers, apps and tools in one place. SourceForge users - Click here to start your Free Trial of Datadog now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
