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100Mb connection copying very slow

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  • 100Mb connection copying very slow

    I have a question for you guys.
    We have setup esx on 2 machines in a coper wired network.
    One of the esx machines is containing 3 vm s
    We use 100 mb network cards and switches.
    The virtual nics in the vm s ara all standard an show 1Gb connection.
    On the esx the virtual switch is setup using 100Mb full duplex.

    When i copy files from a vm disk to a physical server in the network it takes a lot of time before the copy gets done.
    When monitoring ports we see that only about 50% off avaiable bandwith is used at the vm machines nic.
    There are no errors when copying so the duplex settings are all good.
    I have been googeling for this no luck.
    So i am realy stuck here.
    Do you have any idea what could be causing this problem.

    Would greatly appr. any input from you.

  • #2
    Re: 100Mb connection copying very slow

    why are the virtual nics 1 gig if the host box is 100mb? change them to match if you can, and see what happens.

    what type of partition are you trying to copy to and from? from VMFS ro NTFS i assume...

    is windowds file sharing involved?
    its easier to beg forgiveness than ask permission.
    Give karma where karma is due...


    • #3
      Re: 100Mb connection copying very slow

      We just went over this a month ago:

      Pay no attention to the system tray balloon that indicates your virtual NIC is running at 10Mbps (for VLANCE NICs) or 1Gbps (for VMXNET and Flexible NICS). It's hogwash.

      The bottom line is that your VM NIC will transmit and receive as fast as the associated PNIC(s) will allow, or for direct intra virtual switch communication transmit and receive will be as fast as the host bus speed of the VMware server allows.

      You may have used the wrong keywords in google. This has been hashed over about a bazillion times on the VMware forums.

      As far as a file copy performance times, there are a few key variables that will impact this scenario: disk array configuration on the host, fragmentation, network congestion, speed/duplex settings on the PNIC(s), host utilization, etc.

      Keep in mind that almost never will VMware virtualization will outperform like physical hardware. Rule #1 in virtualization: It's not about increasing performance or even achieving equal performance. Virtualization is about maximizing the use of your data center hardware.

      VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+ - VMware Virtualization Evangelist
      My advice has no warranties. Follow at your own risk.