When I had to backup a large database I realized that timeout is a great enemy.
I usualy do the following in order to avoid that problem:
- clear cache
- export all tables into a zip format (not gzip because for some reason it’s more expensive and it fails to generate)
So instead of having, say a 100MB plain text SQL file, you get a 9-10 MB zip file. A huge difference for me that I’m still bound to a 4Mbps connection.