Query on vCPU distribution

[Md. Minhaz Khan]

Dear ALL,

We have already implemented HP IVM in rx6600 server(VM-HOST OS: HP-UX V3 VSE).I have a query on vCPU. The query is, say we have "12" core physical CPU.I have assigned 8 vCPU into VM machine "server1" & "server2" with 40% entitlement. So the summation of Entitlement=(40+40)=80% & this 80% entitlement comes from 8 core Physical server. Now i want to create VM machine "server3" & server4" with 5 vCPU
& 30% Entitlement for each VM machine ("server3" & "server4") . Can i able to do
this ? If Yes then can you give me the breakdown of the CPU distrubtion , If not
also please give the reason in detail?

Thanks
Minhaz

[Vijaykumar_1]

Hello Minhaz,

You can allocate 20 Vcpu's per physical CPU provided you assign the CPU in entitlements.

Also it doen't mean that you allocate 40% of CPU to a VM and other VM's cannot utilize. It is always possible for a VM to share the entitlement CPU's of other VM if they are not accessed.

[Kapil Jha]

>>>if a virtual machine has four vCPUs, and the entitlement is set at 12%, the VM Host
ensures that the equivalent of at least 48% of one physical CPU is available to that virtual machine.

In very somple words.

you have 12 pCPU

server1 8 vCPU with 40% = 40*8=320%
320% of one CPU so almost 3.2 pCPU
server2 same
so server1+ server2= 6.4CPU.
NOW
server4 and server4 5vCPU * 30% = 150% of one CPU
server3/4 need 1.5CPU each so u have enough CPU left to use.

You can cretae VMs without any problem.

BR,
Kapil+

[raiden]

Can someone please put light on this topic as I have same query. I think in this case we can create a server 3 and server 4 vm with 5vcpu but if server 1 and server 2 are already running then the server 3 and server 4 Vm will not start.

Because My understanding is that if server 1 and server 2 are already running and server 3 and 4 are started , then the later will get 30% entitlement each from leftover 4 cores (ie 4 vcpu) , but for 5th vcpu it will not get the 30% as already 80% entitlement has been used by server 1 and 2 from the other 8 cores.

So i think server 3 and 4 VM's will not start. Please clarify whether my understanding is correct or please correct it.

[Torsten.]

Well, the rx6600 has 4 slots, each slot can be populated with a dual-core CPU - so there can be 8 physical cores.


You can assign up to 8 vCPUs for this reason.

The CPUs are shared between HPVMs, so if you balance the entitlement, several virtual machines can share the physical CPUs.