Softaculous

Topic : 99% CPU usage on KVM VPS, extremely slow boot

Posted By: postcd on July 18, 2017, 10:31 pm

Hello,

i installed Virtualizor yesterday on CentOS 6.9 64bit with KVM kernel. Then i activated Multi Virtualization option in Virtualizor and now i have option to also create OpenVZ VPS.

I created two KVM VPS using Virtualizor pre-created OS images (Centos 6.5 centos 7.x), and i see via VNC console that VPS's boot extremely slow, like maybe 100 times slower than normal and VPS usage per VPS is 99% (i confirmed also via command line).

openvz centos 7 minimal VPS works without problem. so seems KVM related problem

Server has enough CPU, it is Xeon E5-2660
SSD drive, Thin LVM, /dev/vg/thin_pool
kernel: 2.6.32-042stab123.9
Virtualizor 2.9.2, patch 5

Please any ideas which commands to do, what to try to discover cause?

Posted By: chirag on July 19, 2017, 12:44 pm | Post: 1

Hi,

Sir this might happen on multivirt.
Due to these issue we do not recommend this solution to our users.

Because this issue ocuurs from kernel side and which is our of our scope of support.

So if possible create 2 different server for each virt.
Or else you can use Virtuozzo. But that is new in Virtualizor and there are many functionalities which are not available inbuilt in Virtuozzo itself so we can not provide it.

Let us know.

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Posted By: postcd on July 19, 2017, 4:53 pm | Post: 2

Thank you alot for a replies and helping to solve this issue!

I think that the solution for this 99% CPU usage issue on a KVM VPS's on OpenVZ kernel is to leave the "CPU %" value set to "0" inside KVM VPS configuration and inside VPS Plan configuration. As you mentioned in your post.

It may be useful if Virtualizor edit the option (CPU %) description and note that it may cause CPU being overloaded on a KVM VPS that is running on the OpenVZ kernel. Or another option is to fix this issue in the Virtualizor so it do not apply this CPU% option in case one is running OpenVZ kernel and trying to setup it on a KVM VPS/plan.

Posted By: chirag on July 21, 2017, 7:56 am | Post: 3

Hi,

Sir we will try to find the solution but we do not recommned to use multivirt as it gives errors due to kernel issue.

Let us know for further information.

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Posted By: postcd on July 22, 2017, 3:15 pm | Post: 4

99% CPU usage by KVM was solved by above mentioned fix. But another issue arised:

Quote

error: Failed to create domain from /etc/libvirt/qemu/v100*.xml
error: Unable to create cgroup for v100*: No such file or directory

It seems that Arvind helped to solve this by advising this:

Quote

libvirtd stopped working so you need to do "service libvirtd restart" then you vpses again start working.

Here your vps was not starting because you have added cpu units 500, Minimum requirement is 1000.

In another words, if "Unable to create cgroup" kind of error appear, one may try:
1. opening VPS configuration (and VPS Plans) in Virtualizor and make sure CPU units are set to "1000" (not less) and CPU % set to "0" (in KVM VPS's, OpenVZ seems not to be affected)
2. command "service libvirtd restart"

Posted By: chirag on July 24, 2017, 10:22 am | Post: 5

Hi,

Sir yes, at the moment those steps should resolve your issue.

Let us know for further information.

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