You say you are keeping dumps and backups. Will those be accessible online?
Is there a read-only html-only version of the tickets? It would be handy if links like this continue to work: https://dev.plone.org/ticket/13606
Is that feasible?
We are not sure yet how it will work. We will look at the data we get from the dump.
We where thinking github + github pages maybe, but we ran out of disk space on our first try, it stopped at about 16 GB. Not sure we want to burden github with that amount of data.
did you try to mirror the site with: wget -mkp https://dev.plone.org/
this should make links to dev.plone.org still work. wget creates for each path a directory and places an index.html file in it - e.g. https://dev.plone.org/ticket/13606 would translate to WEBSERVER_ROOT/ticket/13606/index.html.
I guess the 16GB of data is the whole svn directory, isn't it?
Just a reminder that the date of EOL is getting closer, if you need to move content from dev.plone.org and you have not done it yet now is the time !!!