What issues can I have from not leaving federated server before server reinstall?

[susanthenerd]

Last week, I had decided to do a reinstallation of my VPS with all the data on 2 partitions. I had some issues doing the reinstallation, and now I have access only to the partition with /matrix on it. Is it worth downloading all the data (not important) to my laptop(over slow network) just to not have issues with federation or not.

[aaronraimist]

If you have /matrix then you should have everything you need to continue on with the same install.

In general though, reinstalling a federated server without leaving the rooms shouldn't cause too many problems for you assuming you are going to recreate the same user accounts and join the same rooms. It may just be a bit hard to join rooms initially if you don't have a copy of your old signing key.

If you are planning to use a different domain name, usernames, or join different rooms though then I would recommend you start up the old server and leave all the rooms. It probably won't cause that many problems for you but it will cause more load on all the other servers in those rooms forever into the future. It is impolite to not shutdown your server properly.