[Beowulf] Filesystem benchmarks

[Robert Horton]

Hi,

I'm trying to run some benchmarks on a file server to test the effect of
different filesystems, hardware vs software raid, putting the journal on
a separate device, etc. The machine has 24G of RAM so I'm running

/opt/iozone/bin/iozone -c -C -g 48g -n 48g -i 0 -i 1 -i 2 -q 1m -y 4k -a

The trouble with this is that it's taking an absolute age - the first
random read has been going for about 6 hrs so far. I'm therefore
wondering about using either -e (to include a flush) or -I (to bypass
the cache) with smaller file sizes. Will this still give a useful
comparison? Presumably with -e the read data is still potentially read
from cache?

Any thoughts? Should I be trying a different approach altogether?

Thanks,
Rob