You can manually change the I/O scheduler of the disks and if that works  better for you, put a rule in udev.

Here is mine:

[root@engine rules.d]# cat /etc/udev/rules.d/90-default-io-scheduler.rules
ACTION=="add|change", KERNEL=="sd*[!0-9]", ATTR{queue/scheduler}="none"
ACTION=="add|change", KERNEL=="vd*[!0-9]", ATTR{queue/scheduler}="none"

[root@engine rules.d]# cat /sys/block/vda/queue/scheduler
[none] mq-deadline kyber

Best Regards,
Strahil Nikolov

On Dec 31, 2019 12:30, Demeter Tibor <tdemeter@itsmart.hu> wrote:
Dear Users,

I've successfully upgraded my 4 node hyperconverged system from 4.2.8 to 4.3.7.
After upgrade everything seems to working fine, but the whole management system seems very slow.
Spends many seconds when I clicking on "virtual machines" or I want to edit a virtual machines. 
The speed of vms and the IO is fine.

It is running on a glusterfs (distributed replicate, on 3 node, 9 bricks). There are no errors, everything fine. but terrible slow:(
The engine vm has 0.2-0.3 load. 

What can I do? 

Thanks in advance and I wish Happy New Year!

Regards,
Tibor