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CHR does not support more than two cores, is this true?

Posted: Thu Jul 23, 2020 8:58 pm
by frednks
I have only 1 processor on XEON server with 6 core and 12 threads.

I will use 3 CHR boxes, the idea is to leave 4 cores for each box

my doubt: CHR will use all 4 core, or because it is a virtualized environment he will use a maximum of 2 core?

because I heard that in a virtualized environment CHR does not use more than 2 core per box.

is this true?

does any one use virtualized CHR with 4 or more core, and does it work well?

thanks, waiting for answers!

Re: CHR does not support more than two cores, is this true?

Posted: Fri Jul 24, 2020 11:25 pm
by Hominidae
...with "CHR box", you do mean a VM, right?
Based on the capabilities of your Hypervisor, you can set CPU pinning for each VM.
Setting/allocating up to 4 cores/threads do definitely work for a CHR instance...didn't use more in my setups.

Re: CHR does not support more than two cores, is this true?

Posted: Sat Jul 25, 2020 3:10 pm
by Cha0s
It is not true.

You can have more than 2 cores per CHR instance.
I believe the linux kernel can handle 2048 cores (and that's an old info - this may have been increased in recent years).

BUT, you should NOT proceed with your suggested setup.
Disable hyperthreading on the hypervisor's CPU and only give "real" cores to the CHR instances for maximum performance.

Of course you can "oversubscribe" your hardware and have 4 cores per VM, but if all 3 VMs max out their CPUs, then you will have terrible performance on all of them because there are not enough physical CPU cores.

Re: CHR does not support more than two cores, is this true?

Posted: Sun Jul 26, 2020 2:56 am
by frednks
It is not true.

You can have more than 2 cores per CHR instance.
I believe the linux kernel can handle 2048 cores (and that's an old info - this may have been increased in recent years).

BUT, you should NOT proceed with your suggested setup.
Disable hyperthreading on the hypervisor's CPU and only give "real" cores to the CHR instances for maximum performance.

Of course you can "oversubscribe" your hardware and have 4 cores per VM, but if all 3 VMs max out their CPUs, then you will have terrible performance on all of them because there are not enough physical CPU cores.
Thanks for the answer, this information about Hyper-Threading is very useful.
My server is a Dell PowerEdge, with an intel E5-2420 processor, I entered the intel website on the specifications of that processor and it supports Hyper-Threading technology yes

I will disable this option, it is through the BIOS, already checked on the dell website.

So after I disable the Hyper-Threading option in the BIOS, as this processor of mine has 6 cores and I will use 3 VMs, 1 for each CHR box, I only have 2 cores each

that way I will have 2 cores "dedicated" by CHR and I will not have problems with processor overload
it is? Am I right?

Re: CHR does not support more than two cores, is this true?

Posted: Wed Jul 29, 2020 5:35 pm
by Cha0s
that way I will have 2 cores "dedicated" by CHR and I will not have problems with processor overload
it is? Am I right?
Correct

Re: CHR does not support more than two cores, is this true?

Posted: Wed Aug 05, 2020 7:09 pm
by frednks
To solve!!!

actually CHR supports more than two CORE !! I tested and checked.

It is a little complex when you add a NIC card in hypervision, making this card work correctly in the VM that is CHR, is also a little difficult.

but after everything aligned correctly, it works well.

I recommend!