ESXi

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  • 1.  latency peaks with short frames

    Posted Feb 12, 2015 12:23 PM

    hi ,

    I have a quad core x.86 board which i have checked latency performance.

    The setup is :

    Test equipment GBe port 1 <> 1gbe nic port 1  board --- 1gbe nic port 2  board <> Test equipment GBe port 2

    At first i installed centos 6.5 directly on the board .

    configured the board to be linux router and measured latency over time.

    Got 100 microsec  with steady results in short frames 82Bytes/frame

    Then , i have installed ESXi 5.5 on the board , and on top of it i have created vm centos 6.5 with same image.

    repeated the tests and got non stable results with latency peaks between 5 milisec to 10 milisec.

    when i repeat the test with long frames 1500Bytes the problem is almost gone.

    How can i tune the vmware for low latency on short frames ?

    BR,

    Yoram



  • 2.  RE: latency peaks with short frames

    Posted Feb 12, 2015 01:26 PM

    Which vNIC do you use? Generally, vmxnet3 delivers better performance than e1000/e1000e, but VM has to use proper driver for it (in case of CentOS it means current kernel, as vmxnet3-driver is part of kernel-tree)...



  • 3.  RE: latency peaks with short frames

    Posted Feb 12, 2015 01:30 PM

    Hi ,

    Its VMXNET3 indeed

    BR,

    Yoram