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@yahoo.com> 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@yahoo.com> 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 <http://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 <mailto:root@engine> ~]# cat /sys/block/vda/queue/scheduler [mq-deadline] kyber none [root@engine <mailto: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 _______________________________________________ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-leave@ovirt.org Privacy Statement: https://www.ovirt.org/site/privacy-policy/ oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/YY5ZAPMTD5HUYE...