Server Lags very strange (cant keep up even though the server is good)

Lately our server started to get very strange lags.
We have our server running on a very good root server and it still worked all fine a few days ago.
The internet connection of the root is 1gbit and the hardware is good aswell.

Anyways today the server started to get really strange lags(it doesnt lag for a few seconds and then it lags like hell, it doesnt lag and it lags again) we updatet everything and didnt install any new plugins.

The server also gets the can't keep up message. We also updated every plugin and tried a new server on the same map without plugins(it lagged aswell).

The cpu and the ram usage is really low and the internet connection is good aswell.

We hope you can help us.

(sorry for the many typing mistakes im in a rush)

 

Try my guide, I can't guarantee anything though.

http://forums.bukkit.org/threads/tutorial-reducing-lag-and-possibly-fixing-corrupt-worlds.20911/

 

Nothing to do with corrupt worlds. 1.7 is ripping through memory. See other related threads.