Prometeus - Your 'net consultants !

Hi admin and uncle Sal,

I'm on KVM PM20, what is the CPU type on this node? Besides core number, is there any CPU limitation to the client VPS?
I mean on OVZ you can limit CPU speed, can you do the same with KVM?

Uncle Sal is busy with setting up new servers to solve stock problem, until he is back, I reply your question and he will add his comments:
CPU in KVM is much-much more configurable than in OpenVZ. Not only the number of cores, but also sockets and the power of each core...
If you are asking if the customer has full access to host CPU, the answer is no, the CPU time is shared according to plan specifications, each customer has the share that their plan is granting them and the KVM isolation is much better than OVZ, so they do get that share for sure and also other customers cannot take from your share, so it is guaranteed but also fixed, can't go down, nor up, no matter how the other customers on the node behave, but can be set higher or lower by the admins.
Prometeus does not oversell the hardware, not even memory or disk space and, for this reason, large amounts of CPU are usually left unused.
If you need for some valid reason more CPU, please raise a ticket and Uncle Sal will see what can be done.

Admin

Admin wrote: Prometeus does not oversell the hardware, not even memory or disk space and, for this reason, large amounts of CPU are usually left unused.
If you need for some valid reason more CPU, please raise a ticket and Uncle Sal will see what can be done.
Admin

I couldn't agree with you more..

The case is I have this little personal wordpress blog (well you know how bloated WP is), with nginx and php-fpm. WP is configured with several plugins, including W3TC for caching and CDN.
Using Prometeus node (KVM5, 2CPU, 512MB), every page load (not cached) sometimes will consume 5~10% CPU usage, mostly by php-fpm service. Once the page fully loaded of course then it'll idle to 0% CPU usage.
I have another OVZ VPS, same RAM but with 4 core of i5-2400. On this machine, every page load will only consume not more than ~2% CPU usage.

That is not normal, 5% per visitor.
Do you:
1. Have VirtIO enabled at least for disk ?
2. While WP is bloated, it works well in 128/128 RAM OVZ out of the box. Since your plugins seem to slow your access (you are sure you need cache ?) wouldn't be better without them ? I mean we use some plugins to optimize resources, if they use more than they save is not a good idea.

If you have VirtIO enabled, then probably it is some plugin, try without caching and other optimizations that could be heavy and see what the results are.
If still the cpu goes very high, say, it stays at 100% for a long time, then open a ticket and you will probably get more.

Admin

Yes I enabled virtio for disk. I believe I need page cache.
Do you think page cache compile process bash the CPU?
Thats why I'm asking prometeus CPU type, to compare with my other OVZ VPS that has 4 core i5 CPU which can handle the load perfectly (only ~1% CPU usage). Fyi, both using same configuration of WP.

CPU in KVM is very different than in OVZ. Tell me your KVM node and i will tell you the CPU, but usually nothing is below E3 which is server grade CPU while i5 is desktop grade.
It is like you compare how much the water in the pool rose when you jumped with how much rose in your bathtub, KVM isolates much better and you can't take from the overall CPU while in OVZ you take from the host CPU much more freely.

Admin

Admin wrote: It is like you compare how much the water in the pool rose when you jumped with how much rose in your bathtub
Admin

I don't understand that part M English isn't my native. And by the way I'm on PM20

That is a 24 cores E5 processor, one of the best The load on it is above, as you can see, it is about 40% or so.
There will be no issue to raise your share a bit Raise a ticket.

Now about the analogy I made:
OVZ is like a big pool, a place where many people go have a bath, if you enter in that pool the water does not raise too much.
If you are at home and want to have a bath and enter in your little bathtub, the water raises much more, but it is only for you, you are not afraid you get a disease from other people, that you get splashed when they jump in water or that the water is a bit dirty.
It is the same between OVZ and KVM, you are not comparing the same thing.
For more information, read the comparison I made here between various techniques and how to choose your VPS:
viewtopic.php?f=8&t=851

Admin

Admin wrote: Now about the analogy I made:
OVZ is like a big pool, a place where many people go have a bath, if you enter in that pool the water does not raise too much.
If you are at home and want to have a bath and enter in your little bathtub, the water raises much more, but it is only for you, you are not afraid you get a disease from other people, that you get splashed when they jump in water or that the water is a bit dirty.
Admin

Ah I understand now. I seem to have an incorrect understanding of the KVM & OVZ from the beginning.
I thought it was KVM that has "1 big shared pool" for the CPU, and OVZ was on complete CPU separation. But it seems just the opposite

Admin wrote: There will be no issue to raise your share a bit Raise a ticket.

Will do!

It seems like I missed the very first question directed to me

I promise to do a better job in future