Saving entries in admin panel
To debug where the delay is, you can enable devMode, which will write out a bunch of code and database profiling information to your log files in craft/storage/runtime/logs.

After you do that, save an entry then find that request in the log files.  You can look at the timestamps on that request to see what part of the code the 30 second delay is occurring on, which will point you in the direction of the underlying problem.