Error when trying to download VHD file RRS feed

  • Question

  • From: Marko Hrovatic @brgrz via Twitter

    After couple of retries I always encounter "Unknown network error" when trying to download 50GB VHD file. I'm on quite reliable fast broadband connection and always download huge files without issues. What is going on? 



    Thursday, March 10, 2016 10:54 PM

All replies

  • Just a note, do I have to shutdown the VM the VHD is attached to (it is a data disk)?
    Friday, March 11, 2016 8:44 AM
  • Hi Marko,

    How are you trying to download the file? Are you browsing through storage accounts -> blobs in the new portal ( or by some other means, such as PowerShell, CLI, etc.? Also, how far does the download get when you encounter the error?



    Monday, March 14, 2016 4:47 PM
  • I was trying to download through the storage containers in the old portal at I wasn't able to find the vhd in the new portal.
    Monday, March 14, 2016 7:38 PM
  • In the new portal, choose Browse->Storage Accounts (Classic)->Blobs->vhds... and there is a download option. This will help rule out if it is an issue with old portal.

    You could rule out an issue with your browser by trying a storage explorer to download the file (like - if it should fail I hope you will also get a more meaningful message..

    Monday, March 14, 2016 10:34 PM
  • Thanks for the Storage Explorer suggestion. I installed it and connected to our account, then proceeded with VHD download. I left it overnight and it got to 94% but now it stopped and the transfer rate fell to 0%. It's been like that for few hours so I'm about to cancel it.
    Tuesday, March 15, 2016 7:32 AM
  • I'll ask again - do I have to stop the VM to be able to download successfully? That could be impossible for us since download takes at least few hours and we cannot stand the downtime. Is it possible to create a snapshot of the VHD and download it?
    Tuesday, March 15, 2016 7:34 AM
  • It's not recommended to download an attached drive from a running VM. If the VM is running it is recommended to download from a snapshot. The main reason is that if there are files being edited on the disk as you're downloading there is a possibility of corruption. I've not seen the problem you mention caused by this though - so not sure if that would be why the download trails off. Instead I'm wondering if the tools being used (browser, explorer) are optimized to handle such large files.

    Do you have access to Azure PowerShell? Save-AzureVHD is optimized to handle large VHDs, so the best approach would be to use a tool like this, against a snapshot or copy of a snapshot.

    Tuesday, March 15, 2016 6:05 PM