Dear Com, from time to time I typed "save-all" in the bukkit command terminal. I thought this creates a backup of the current world. Yesterday we had a giant TNT session and destroyed huge amounts of our buildings and techs. Now I want to restore a saved world but there's no restore command or something similar. Please don't tellme that we have no backup 8-{
I thought that just wrote what was in memory back to the worlds files on disk. It didn't actually create a backup of any kind. I'm no authority on it though...... For your sake I hope I am wrong
After your TNT session, you /stopped the server. /stop also does a save-all. In other words, it wrote over your last save. For backups you need to run a batch or shell on your server that creates real backups. There's plugins for that but I recommend doing OS stuff on OS level, and not a java plugin for Minecraft.
May I also recommend you get the plugin Backup? It backs up on timed intervals and deletes old ones so you wont overflow with memory. It can even backup your plugins folder.