@Elwood: The threshold is in KB, just as in GUI:
https://winscp.net/eng/docs/ui_pref_resume

I've corrected the space in the get documentation. Thanks.

Wow, this is a 20 years old thread ;-)

Martin, I have this kind of issue.
A transfer was aborted so a file was not downloaded completely. When I run WinSCP again with -resumesupport=on, it says:

The command line I use is:

Am I missing something?
Oh, I think I understand. The transfer that was aborted was not done with "resumesupport". I used it only on the second attempt. I assume now that I should always use "resumesupport". Am I correct?

Note on the get manual page, it says

-resumesupport= <state>

There is an extra space.

Could you define on these pages, how to define a threshold? Is it in KB?
or can we use something like -resumesupport=100MB?

Thanks

If the transfer is broken, partially uploaded file should remain in target directory with extension .filepart. When you attempt to transfer the same file, WinSCP detects aborted transfer and let's you choose if you want to resume or restart transfer.

Check your preferences if you have transfer resume enabled (Transfer tab of Preferences dialog).

I am using SFTP. How do I resume the file transfer?

WinSCP supports transfer resume automatically, but only for SFTP protocol. You are probably using SCP. Switch to SFTP (see Session tab of login dialog).

I'm downloading mandrake 10 isos from a friends machine in a different state. I get cut off and have to restart the download. This will be my 3rd attempt at downloading the iso for cd2.

Is there any way to resume a partially downloaded file after being disconnected from the dowload machine?