Large site import

Background

I’m trying to import a large site (1000+ Posts, ~3 GB of images) from one domain into another domain running a multisite.

I’m using the Tools -> Export to create an XML file and then the Tools -> Import -> WordPress feature to import the XML file. I check the option to import media / attachment files as well as posts. Before I do the import I make sure I manually configure the new site under my multisite so that it has the same config and user accounts.

Problem
The problem I run into, after trying multiple times is that the process always fails, either with or without a

All done. Have fun!

message at the bottom and always with lots and lots of

Failed to import Media

error messages. I also get the following error message in my server logs each time I try this import:

PHP Fatal error: Maximum execution time of 60 seconds exceeded

I’ve tried fixing the above with a set_time_limit(), but the process still fails and I get the same error log.

I’ve also tried importing with the option to import media/attachments unchecked, but the resulting Posts are using the image URLs from the site I’m trying to import.

I’ve also tried importing the site in chunks, but when I export all Posts for a given date range, I don’t get any actual content in my XML export file.

Lastly I’ve tried some Python code I found online to try splitting up the large XML export file, but no luck there – I think the code is too old (5+ years) and probably only works with an older version of WordPress.

My only other thought is to try modifying the import plugin code so that when it tries to import media, it just updates the Posts with the new URL for media and attachments but doesn’t actually try to grab them. If that worked I could then just manually copy over the ~3 GB of images and attachments to the new uploads folder. But I’m hoping there is an easier solution?

Any suggestions?