Basically have been working over the weekend converting a Single 2008 Server to the iSCSI ESXi 5.0 Environment (Fairly Straight Forward Right!) Well started getting serious speed issues and I know there is no performance problems with the server its converting from to where its going to. Just to show you how bad of a performance problem see this screenshot:

*Not a Pretty Site!

Anyway found this article which turns off SSL encryption between the host taking the conversion and the ESXi enviroment and the speed is 50x faster. Unfrotuantely I do not have a screenshot to show but next time I do a conversion I will update to show the difference.

Follow these steps to resolve:

Disable NFC SSL in the converter configuration file (steps from the converter release notes):

1) Disable NFC SSL 1.Open the converter-worker.xml configuration file. It is usually located in

2) C:ProgramDataVMwareVMware vCenter Converter Standalone folder.Set the key

3) Config/nfc/useSsl to false. Save the configuration file.Restart the VMware vCenter Converter Standalone Worker service

Note* Make sure you get the right UseSSL as its referenced under the use Soap Section as well:


Below is the speed increase when you do the above:
(This still not as Fast as I would hope but is better than what was previously stated – Also you should note this Server is heavy on SQL which I know has a big impact on the Conversion)

7 thoughts on “VMWARE Converter 5.0 Slow Transfer/Speed – SSL

  1. You, my friend, are my savior. I was getting 399KB/s and now after making this change am getting 8.9MB/s. As you stated, not as great as I would expect, but this is absolutely awesome in comparison to what I was getting previously. THANK YOU!!!!

  2. Gents,

    I removed / changed the useSSL section but it seems, that my standalone converter still uses SSL with a very slow speed. I tried this on several workstations and I do allways receive the same result! 🙁 Any suggestions, how this will work in real life?

    Need to convert approx. 550 GB…

    Thanks in advance…


    1. Hi,

      Can you confirm its the right UseSSL Section as there is a few I believe

      “Note* Make sure you get the right UseSSL as its referenced under the use Soap Section as well:”

      Also have you restarted the service?

      “Restart the VMware vCenter Converter Standalone Worker service” or even the server?


  3. Thank you,

    The conversion went from 6 hours to 15 minutes 🙂
    50MB/sec instead of 700kb/sec

    And a little note, if you use a windows 2003 or xp machine to convert the VMs, the file is located at the following location.

    c:documents and settingsall usersapplication datavmwarevmware vcenter converter standalone

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