can drop db pls?

Home.md

@@ -16,3 +16,18 @@ Run this sql query on your db:
 Manually resetting passwords:
 ---
 See https://github.com/matrix-org/synapse/blob/master/README.rst#password-reset
+
+I have a problem with my server. Can I just delete my database and start again?
+---
+Deleting your database is unlikely to make anything better. 
+
+It's easy to make the mistake of thinking that you can start again from a clean slate by dropping your database, but things don't work like that in a federated network: lots of other servers have information about your server.
+
+For example: other servers might think that you are in a room, your server will think that you are not, and you'll probably be unable to interact with that room in a sensible way ever again.
+
+In general, there are better solutions to any problem than dropping the database. Come and seek help in https://matrix.to/#/#matrix:matrix.org or https://matrix.to/#/#matrix-dev:matrix.org.
+
+There are two exceptions when it might be sensible to delete your database and start again:
+* You have *never* joined any rooms which are federated with other servers. For instance, a local deployment which the outside world can't talk to. 
+* You are changing the `server_name` in the homeserver configuration. In effect this makes your server a completely new one from the point of view of the network, so in this case it makes sense to start with a clean database.
+(In both cases you probably also want to clear out the media_store.)