We presently have directions outlining that when a mailing list is renamed, we put in apache redirection pages for the listinfo page, and we migrate the archives, but leave a copy of the old archives in place. This makes sense, in that the old archives are linked to outside of the mailman software; however there is no reason to do this via duplicate archives when an apache redirect would suffice.

As such, I'd like to append archive redirections to all the listinfo redirections, after confirming each one has full archive content on the new list as well as the old list archives. As long as the new archives are inclusive, I'll append a new rewrite to the new archives and confirm it is working. Once they are confirmed working, I'll remove all the old list archives.

This will de-duplicate list archive data considerably, allowing for the ongoing migration to have less data to crunch. (Plus why keep duplicate data anyhow?)

In a quick test of the old foundation-l to new wikimedia-l shows a few odd items, that I think are attributed to list rebuilds and recompression over time:

https://lists.wikimedia.org/pipermail/wikimedia-l/
https://lists.wikimedia.org/pipermail/wikimedia-l/2004-April/thread.html

https://lists.wikimedia.org/pipermail/foundation-l/
https://lists.wikimedia.org/pipermail/foundation-l/2004-April/thread.html

So the actual number of messages/subject/author have remained unchanged, but he overall threading indentation and overall archive size per month has. I've attributed this to the fact the active list has more recently had arch rebuilds.