Hello,
i have a a1000 connected to an e6500. There's a raid 10 (12 disks) on the a1000.
If i do a
dd if=/dev/zero of=/mnt/1 bs=1024k count=1000
and then look at iostat it tells me there's a kw/s of 25000.
But if i do a
dd of=/dev/zero if=/mnt/1 bs=1024k count=1000
then i see only a rw/s of 13000.
So the read performance is smaller then the write performance?
Can someone tell me what i am doing wrong?
Regards
If a raid 10 made up of 12 disks is 6 disks in a striped volume mirrored against another volume of 6 disks in a striped volume, the the mirroring process (which has to write to both striped volumes) slows down writes compared with reading (which only has to read from one of the striped volumes), normally.
I think writing to /dev/zero is not a good idea, I would try writing to /dev/null instead.
Reading from /dev/random would be interesting to compare with reading from /dev/zero also?