[ovirt-users] Re: Hosted Engine I/O scheduler

Checked this on mine, see the same thing. Switching the engine to noop definitely feels more responsive. I checked on some VMs as well, it looks like virtio drives (vda, vdb….) get mq-deadline by default, but virtscsi gets noop. I used to think the tuned profile for virtual-guest would set noop, but apparently not…   -Darrell > On Mar 18, 2019, at 1:58 AM, Strahil Nikolov <hunter86_bg(a)yahoo.com&gt; wrote: > > Hi All, > > I have changed my I/O scheduler to none and here are the results so far: > > Before (mq-deadline): > Adding a disk to VM (initial creation) START:     2019-03-17 16:34:46.709 > Adding a disk to VM (initial creation) COMPLETED: 2019-03-17 16:45:17.996 > > After (none): > Adding a disk to VM (initial creation) START:     2019-03-18 08:52:02.xxx > Adding a disk to VM (initial creation) COMPLETED: 2019-03-18 08:52:20.xxx > > Of course the results are inconclusive, as I have tested only once - but I feel the engine more responsive. > > Best Regards, > Strahil Nikolov > > В неделя, 17 март 2019 г., 18:30:23 ч. Гринуич+2, Strahil <hunter86_bg(a)yahoo.com&gt; написа: > > > Dear All, > > I have just noticed that my Hosted Engine has  a strange I/O scheduler: > > Last login: Sun Mar 17 18:14:26 2019 from 192.168.1.43 > [root@engine ~]# cat /sys/block/vda/queue/scheduler > [mq-deadline] kyber none > [root@engine ~]# > > Based on my experience  anything than noop/none  is useless and performance degrading  for a VM. > > Is there any reason that we have this scheduler ? > It is quite pointless  to process (and delay) the I/O in the VM and then process (and again delay)  on Host Level . > > If there is no reason to keep the deadline, I will open a bug about it. > > Best Regards, > Strahil Nikolov > > Dear All, > > I have just noticed that my Hosted Engine has  a strange I/O scheduler: > > Last login: Sun Mar 17 18:14:26 2019 from 192.168.1.43 > [root@engine ~]# cat /sys/block/vda/queue/scheduler > [mq-deadline] kyber none > [root@engine ~]# > > Based on my experience  anything than noop/none  is useless and performance degrading  for a VM. > >