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Using the VMware vCenter Server 4.x,5.x and 6.0 datastore browser to download or copy a powered-on virtual machine's .vmx and .nvram files fails (1019286)

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  • Downloading the .vmx or .nvram file of a powered-on virtual machine from the datastore browser in vSphere Client fails.
  • You see the error:

    Expected put message. Got: ERROR
  • Copying the .vmxor .nvram file from the datastore browser in vSphere Client fails.
  • You see the error:

    Unable to access file [filename]
  • Using to get the .vmxor .nvram  file directly from an ESX\ESXi host that can see the datastore holding these files fails.
  • You see the error:

    Error: File can not be downloaded to <destination path>
  • Connecting to the VMware vCenter Server URL (http://VC-hostname), navigating from the web-based the datastore browser link to the .vmx or .nvram file of a powered-on virtual machine and attempting to download the files fails with an http error or the error: 

    The downloaded file is of size 0 bytes 
  • When set to trivia logging, in the vCenter Server's vpxd logs, you see the entry:

    Sending soap request to [TCP:<ESX-HostName>:<Port>]: nfcMakeTicketByDatastore.

    You can enable trivia logging for vCenter Server to capture information about the ESX\ESXi host which vCenter Server selects to service the download request. For more information, see Enabling trivia logging in vCenter Server (1001584).
  • In the vpxa.log file for the ESX\ESXi host, you see entries similar to:

    [2010-02-04 14:26:40.367 0xf7bbab90 info 'Libs'] [NFC DEBUG] NfcFileRawOpen: failed to open: Generic error..
    [2010-02-04 14:26:40.367 0xf7bbab90 warning 'Libs'] [NFC ERROR] NfcFile_Open: Open failed:
    [2010-02-04 14:26:40.367 0xf7bbab90 warning 'Libs'] [NFC ERROR] NfcStartFileSend : failed to open file

     Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.


This issue may occur when the .vmx or the .nvram files are stored on a shared datastore (that is, if the datastore is visible to more than one ESX\ESXi host). The ESX\ESXi host holds a lock to these files when the virtual machines is powered-on, so attempting to download these files from another ESX\ESXi host results in failure.
When browsing the web-based datastore browser or vSphere Client datastore browser connecting to a vCenter Server, vCenter Server chooses an ESX\ESXi host to service the download or copy operation. Problems occur if this ESX\ESXi host is not the host on which the powered-on virtual machine is running. Similarly, the download or copy operation can fail when browsing in a web-based datastore browser or vSphere Client's datastore browser after connecting to the ESX\ESXi host where the virtual machine is not running but the datastore is visible.
To work around this issue, try one of these options:
  • Use the datastore browser in vSphere Client directly connected to the ESX\ESXi host on which the virtual machine (whose .vmx or .nvram files are of interest) is running.
  • Use and connect directly to the ESX\ESXi host on which the virtual machine (whose .vmx or .nvram files are of interest) is running.
  • Use a web-based datastore browser by connecting a browser directly to the ESX\ESXi host on which the virtual machine (whose .vmx or .nvram files are of interest) is running.
  • In vCenter Server 4.0 Update 2 and vCenter Server 4.1 or later, use a web-based datastore browser by connecting a browser to vCenter Server.

    Note: If the download fails, retry the download operation.
Note: If the preceding options do not resolve your issue, contact VMware Support. For more information, see How to Submit a Support Request.

Additional Information

If the workarounds listed above do not work, you can power off the virtual machine and then attempt the file copy again. If the operation fails even when the virtual machine is powered off, it is possible that a backup process or some other process is holding a stale lock on the file.
For other troubleshooting options, see Investigating virtual machine file locks on ESXi/ESX (10051).


cannot-download-vmx-file cannot-download-nvram-file

See Also

Request a Product Feature

To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.


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  • 51 Ratings