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Degraded Windows network file copy performance after full ESXi 5 VMware Tools installation


After a full install of the ESXi 5 VMware Tools:
  • Copying files to or from a CIFS share takes considerably longer than before the install
  • The impact is especially noticeable if one side of the copy is not capable of SMB 2.0
  • Disabling the VMCI or the vsepflt driver resolves the performance issue (requires reboot)
  • Unloading the vsepflt filter resolves the performance issue (no reboot required)


Starting with ESXi 5.0, VMware Tools ships with the vShield Endpoint filter driver. This driver is automatically loaded when VMware Tools are installed using the Full option, rather than the Typical default.

Due to certain handling implementations in the filter driver and restrictions in the filter driver framework, file copy operations to or from a Windows network share might have noticeable impacted performance.


If you are not using vShield Endpoint for antivirus protection, unload the filter driver and disable it.    

  1. Click Start > Run, type cmd and press Enter to open a command prompt.
  2. To view the currently loaded filters, run the command:

    C:\> fltmc

    Filter Name             Num Instances    Altitude    Frame
    ----------------------  -------------  ------------  -----
    vsepflt                         5       328200         0
    luafv                           1       135000         0

  3. To unload the vsepflt driver, run the command:

    C:\> fltmc unload vsepflt

  4. To prevent the vsepflt driver from loading on subsequent reboots:

    Note: Before making any registry modifications, ensure that you have a current and valid backup of the registry and the virtual machine. For more information on backing up and restoring the registry, see the Microsoft article 136393.

    1. Click Start > Run, type regedit, and press Enter. The Registry Editor window opens.
    2. Navigate to:


    3. Locate the Start DWORD.
    4. Right-click Start and click Modify...
    5. Change the value to 4 and press OK.
    6. Click File > Exit to close the Registry Editor.

  5. Based on VMware KB 2034490

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