Re: [CentOS] Disk Elevator

Depends is the best answer. It really depends on LVM and the other block layer devices. As the io requests descend down the different layers they will enter multiple request_queues, each request_queue will have and io scheduler assigned to it, either the system default or one of the others, or one of the block devices own, so it is hard to say. Only by testing can you know for sure. In my tests LVM is very good with unnoticeable overhead going to hardware RAID, but if you use MD RAID then your experience might be different. Hope this helps clarify.

It does, and I should have specified at the outset that this was with respect to hardware raid.