I have some virtual machines running Ubuntu cloud-based image 14.04-1 LTS version. I wanted to see the IO performance of different IO schedulers on the VM so I went to
/sys/block/<drive>/queue/scheduler on the guest OS to change the IO scheduler. Usually, there should be
noop to choose. But what I saw is
none. Does it mean that Canonical has removed the I/O scheduler in the cloud-based image or the scheduler
none here is the renamed
noop scheduler? and what happens if we don't have an I/O scheduler in the system? All the io requests were directly sent the host in FIFO order?
Thanks for shed some light!