Given your question are you about to come back with a
case where you are not
seeing this?
As a follow-up, I tested this on UFS and ZFS. UFS does very poorly: the I/O
rate drops off quickly when you add processes while reading the same blocks
from the same file at the same time. I don't
On February 26, 2007 9:05:21 AM -0800 Jeff Davis
But you have to be aware that logically sequential
reads do not
necessarily translate into physically sequential
reads with zfs. zfs
I understand that the COW design can fragment files. I'm still trying to
understand how that would affect
Given your question are you about to come back with a
case where you are not
seeing this?
Actually, the case where I saw the bad behavior was in Linux using the CFQ I/O
scheduler. When reading the same file sequentially, adding processes
drastically reduced total disk throughput (single
if you have N processes reading the same file sequentially (where file size is
much greater than physical memory) from the same starting position, should I
expect that all N processes finish in the same time as if it were a single
process?
In other words, if you have one process that reads
