AzCopy fails with "The transfer failed: Unable to write data to the transport connection"


  • Hello,

    How to fix this error?

    Azcopy is run for one file of about 1GB size like this under Administrator:

    azcopy /source:PATHTOFILE /dest:https://PATHTOAZURECONTAINER /destkey:OURKEY / /S /Y /V:PATHTOFILELOG.log

    It fails with this:

    > [2017/02/02 14:36:45.528+01:00][ERROR] FILENAMEHERE: The transfer failed: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.

    It copied successfully for small files.

    • Edited by Artyom K Thursday, February 2, 2017 1:55 PM
    Thursday, February 2, 2017 1:52 PM

All replies

  • I think it probably timed out ...

    what happens if you do the same with Azure Storage Explorer?

    Cheers Christophe Kindly click Mark as Answer on the post that helps you, this can be beneficial to other community members reading the thread and Vote as Helpful Azure Fanatic!

    Thursday, February 2, 2017 3:44 PM
  • The error might caused by temperately network issue. You can resume AzCopy transfer with same commandline. AzCopy support to resume from the failure point in the file.

    If you meet the failure repeatedly in resume, you might can consider to reduce the transfer threads count by "/nc" parameter (e.g.: "/nc:10"). The default threads count is: CPU core * 8

    Tuesday, February 21, 2017 1:47 AM