Remove existing monsters/control day and weather

[Narroo]

Is there a way, using MCServer, to remove currently existing mobs? Or should I use something like MCEdit?

Also, how do I fix the day/night cycle and the weather cycle? I want it to by sunny 24/7.

Thanks!

[tonibm19]

To kill all mobs you could use ClearLagg or WE /butcher

Permanent water could be done with a plugin.

[xoft]

To remove all mobs, you need to use a plugin. As Tonibm19 already mentioned, ClearLagg or WorldEdit will do it for you.
If you don't want mobs to even spawn in your world at all, you can set the "[Monsters].AnimalsOn" value in the world.ini config file.

There's currently no plugin to disable the day/night cycle nor weather changes. You can use the Core plugin's /time and /weather commands for setting each, but the cycle will continue. I've been wanting a plugin to control this more thoroughly for some time, if you can write one, that'd be great.