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I need to download a 10 GB VM file from a network drive. The problem is I periodically need to access a VPN connection which disconnects the network drive.

I am not able to resume the download after I disconnect from the VPN and re-access the network drive. I've tried 4 times.

I need the file as soon as possible for work. Will I need to wait until I finish working today to start the download and let it run over night?

I'm using Windows 7.

Travis
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  • Answer/comments summary: robocopy /r:3 /w:10 /z c:\src c:\dest file1.txt file2.txt. Adjust amount of retries (r) and wait seconds between retries (w). File names are optional. – Paul Jun 23 '23 at 18:35

1 Answers1

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You should be able to use the command line tool Robocopy, which supports resuming transfers after network connections drop. It's now built into Windows 7. You can type robocopy /? to see all of the options. I suspect the section entitled Retry Options is most relevant to what you're doing. In particular, it might be worth it to set this parameter

/W:n :: Wait time between retries: default is 30 seconds.

If you are usually connecting to the VPN for periods of 10 or 20 minutes, it might be worth it to increase this retry wait time.

As an alternative, you may be able to set up the VPN connection so that you are still able to access local network resources. Some VPN setups allow this, and others don't.

dsolimano
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    Please, correct me if I'm wrong, but robocopy doesn't resume download, it just starts over... So, if the file big enough, and the connection drops are frequent, you won't get your file... – Sergey Kostrukov Jan 30 '15 at 14:22
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    @SergeyKostrukov look at https://technet.microsoft.com/en-us/library/cc733145.aspx, option /z. – dsolimano Jan 30 '15 at 14:37
  • Thanks, will take a look at the meaning of the /z and /b modes. – Sergey Kostrukov Jan 30 '15 at 19:39
  • It works with the /Z flag, although it doesn't retry automatically on disconnect, you have to reconnect the VPN and then relaunch exactly the same command you did the first time, and Robocopy will pick up where it stopped during the large file copy. – gaborous Sep 18 '21 at 12:27
  • Robocopy /Z works but it's very slow .e.g. on a 1GBit link, it gets around 250Mbit/s. – Damien Jun 13 '23 at 04:02