Johan Hendriks wrote: >> If somebody still have questions, after some UFS parameters tuning I've >> got with the same tiotest tool: >> - Random Write latency - 15us, >> - Random Read latency - 7us. > > What kind of UFS parameter tunings.
To maximize write-back delay. I've mounted file system asynchronously and increased vfs.dirtybufthresh and vfs.hidirtybuffers values ten times. > If things ar tuned for old hardware, which hardware are we talking about > i386? Or i486? > Maybe we should set the defaults for AMD64 in a way that modern hardware > can handle. > > AMD64 is a for modern hardware, it does not run on a pentium3. It is not a tuning for hardware. It is mostly tuning for sanity. Enormous write-back without using additional technics increase chance of data loss on power-outage, but doesn't give principal effect under constant load. This test is so easy to cheat, as it runs only few seconds and completely ignores cache effects. I believe that the same test with work file size increased by 100 times would show completely different results. -- Alexander Motin _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
