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oracle VM server

User_414UD
User_414UD Member Posts: 1 Green Ribbon

hi everybody

i hope you are all fine.

I want to understand the relation between processor on my virtual machines on ovm server and the physical processors.

i have 2 socket with 4 cores per socket and 1 threads per core. on my ovm manager when i want to create a virtual machine i see that i can increase the number of processor to 128 because i use hvm virtual machine.

if the number of vcpu on my virtual machine is (socket * number of core per socket * thread per socket). what is the meaning of the 128 processors when i want to create a virtual machines ?

What is the impact if i use all the 128 processors on a virtual machines ?

if i do hard partitionning for exemple i will use cpu 0-3 in my case and on the virtual machine i use all the 128 processors what is the meaning.


i really dont understand this part.

please i want your help.

thank you

Answers

  • Nik
    Nik Blocked Member Posts: 2,879 Bronze Crown

    Hi.

    I am not guru of OLVM.

    I hope other man can clear this questions more detail.

    Answer will depend from reason of this question. ( How it's work ? or You need some special requirements).

    See Part: CPU Topology.


    1 How many resource (vCPU) have your server ?

    You have: 2 socket with 4 cores per socket and 1 threads per core = 8 vCPU.

    (Check number of "Logical CPU cores" for host)

    2 Even system allow create vm with 128 vCPU - it's do not mean that system allow start this VM.

    They just say that do not have this resources.

    OLVM Cluster have tunable parameter: "Count Thread as Core" so OLVM can count threads as core.


    By default - OLVM do not bind VM to CPU.

    So You can start more VM, that really have cores. In this case VM will share available CPU resources.

    Behavior of VMs and system depends how VMs utilize CPU. ( When You configure VM with 10 Cores, it' dos not mean that VM will fully utilize it. VM can utilize it, in case have workloads.


    3 When VM have configured with some cores, it's should map this virtual resources on general topology.

    So You can configure system as many single-Cores CPU or as Multi-cores cpu. This options can affect on schedule of this tasks and select Host for placement this VM. General recommendation - use default (single cores - single thread configuration).


    I hope I can clear some questions.

    Create test installation and try it. It will be more native and quickly for study.


    Regards,

    Nik