>>1163>Was the system simply unable to keep up with all of the images and posts
That tends to happen. Image and thumbnail are fetched after the post has been inserted into the database (this is because of the way de-duplication is handled). When posting rates are high we can't insert fast enough to keep up and the images might be gone by the time we get there or the server is so starved for IO that it can't complete the file download.
Ideally this could be solved by tweaking the database for faster inserts or by using faster hardware or by programming another way to fetch media. I planned to disable some database procedures but didn't get a change and ended up just riding it out.
All in all I am pleased that we got anything archived at all from such a chaotic time.