4 Comments

  1. Ken

    Hello, I’m a SQL Server DBA trying to performance tune on a virtual machine. I have read-only access to my companies vSphere Web Client (version 5.5.0) but cannot locate the CPU ready time. Sorry for such a noob question but can you explain how to navigate to this display? Alternatively, Do I need to perform a desktop client installation of the VMware administration tool to see this?

    Any help appreciated.

    Ken

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  2. Dave

    Would the correct calculation not be as follows?

    ((CPU summation value / ( * 1000)) * 100 = % CPU ready)/Number of vCpus

    I thought the recommendation was not over 10% per cpu?

    Reply
    1. anthony

      Hey Dave,
      I had used this as a reference (KB 2002181) which shows you how ESXTOP converts between the metrics for the VM (as a whole) regarding CPU ready time, rather than per-core. Because VMware uses a Gang-CPU scheduler for VMs, it doesn’t matter whether one core or more cores need to wait – they all need to be available at the same time for the VM. For example, if one core constantly needs to wait, the overall VM will suffer. Does this help clear things up?

      Reply
    2. RudiK

      Agree, vSphere adds all vCPU together.
      So if a VM is waiting 10ms all 4 vCPU wait for 10ms total dispalyed is 40ms.
      So when you calculate CPU Ready you have to devide bij nr of vCPU’s

      Reply

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