Re: raid0 vs. raid5 read performance

[Jan Edler]

I have tried various values for chunksize, but the difference
seems to be <10%.  Raid5 is always significantly slower than raid0,
maybe 35MB/s compared to 60MB/s.
I use mke2fs -b4096 -i32768 -Rstride=xxx, with xxx being chunksize / 4k.

This is still a mystery to me.

I also notice that sequential reading of /dev/md0 is significantly
slower than reading a file on a mounted FS on /dev/md0.
I suppose there is more aggressive readahead happening
in the mounted FS for some reason.

Jan Edler