Logs from chats in rooms?

Is it possible to preview historical messages send for pernament room in Spark?

I can do that for single contact, cannot see same for conference rooms

I’m not 100% sure what you are looking for, but it seems what you would like is to see previous chat (from before you enter) in chatrooms?

In Openfire Server, that is controlled through the admin console under Group Chat > Group Chat Settings > History Settings

You can specify either the entire chat to be sent or just the last xx number of lines.