Stephen John Smoogen wrote:
On Fri, Feb 27, 2009 at 12:31 AM, Andrzej Szymański szymans@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
- what is filefrag and where is it from?
filefrag comes with e2fsprogs-1.39-15.el5
- 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
- What happens if you don't use fsync on the dd.
No significant change.
- What happens if you use larger/smaller bs
No siginficant change.
- 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