2009/9/30 Dieter <[email protected]>: >> > My question is why is FreeBSD's disk i/o performance so bad? >> >> As I mentioned... this was discussed actively in slashdot. You will find >> there many good comments on this. > > All I saw in slashdot was a ffs vs ext comment. I don't believe the problems > I'm seeing are filesystem related. > >> > Not just in the benchmarks with debugging on, but in real world usage >> > where it actually matters. >> >> Are you saying this from actual experience or from reading other people's >> comments? > > Here is a specific demo of one disk i/o problem I'm seeing. Should be > easy to reproduce? > > http://lists.freebsd.org/pipermail/freebsd-performance/2008-July/003533.html > > This was over a year ago, so add 7.1 to the list of versions with the problem. > I believe that the > swap_pager: indefinite wait buffer: bufobj: 0, blkno: 1148109, size: 4096 > messages I'm getting are the same problem. A user process is hogging > the bottleneck (disk buffer cache?) and the swapper/pager is getting starved.
Sorry, do you have a PR/describing e-mail with this issue? Can you be a bit more precise? The problem reported in the earlier post, however, is interesting and worths more analysis. More speficially, would you be interested in reproducing and playing a bit with some diagnostic tool/configurations I can point you at? Attilio -- Peace can only be achieved by understanding - A. Einstein _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "[email protected]"
