Stephen John Smoogen wrote: > On Fri, Feb 27, 2009 at 12:31 AM, Andrzej Szymański <szymans at agh.edu.pl> wrote: >> Hello, >> >> Does anybody know how to avoid the file fragmentation when a file is >> created over NFSv3? >> >> A file created locally is OK: >> dd bs=32k if=/dev/zero of=test count=32x1024 conv=fsync >> filefrag test >> test: 10 extents found, perfection would be 9 extents >> >> When I create the file in the same dir, but from another machine, >> mounted over NFS: >> >> filefrag test >> test: 4833 extents found, perfection would be 9 extents > > 1) what is filefrag and where is it from? filefrag comes with e2fsprogs-1.39-15.el5 > 2) Have you played with adding/subtracting threads to see if that helps? 8 threads - 3300 - 5000 extents 2 threads ~3000 extents 1 thread ~2000 extents (this one I've checked both with tcp and udp) so it drops with decreasing number of threads > 3) What happens if you don't use fsync on the dd. No significant change. > 4) What happens if you use larger/smaller bs No siginficant change. > 5) Is the rsize/wsize onthe server 32768 or some other number. I > thought the default w/size on an export was 512 or some small number. 32768 is my setting. But when I leave it at the default the result is the same. Andrzej