The server was down for 2 hours, managed to have it restarted. It seems that something either froze or crashed the whole machine. I tried to reboot it but some bad config from the provider failed to connect it properly to the network, so that took it a bit longer to come back up. It’s back up now.

There seems to be some permission issue or otherwise where the data on the ramdisk cannot be saved. It affects the hunger world and the draftlands. I am getting this here and do not know why:

[12:47:24 WARN]: net.minecraft.server.v1_7_R1.ExceptionWorldConflict: The save is being accessed from another location, aborting
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.WorldNBTStorage.checkSession(WorldNBTStorage.java:72)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.World.F(World.java:2688)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.WorldServer.a(WorldServer.java:812)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.WorldServer.save(WorldServer.java:796)
 [12:47:24 WARN]:        at org.bukkit.craftbukkit.v1_7_R1.CraftWorld.save(CraftWorld.java:664)
 [12:47:24 WARN]:        at org.bukkit.command.defaults.SaveCommand.execute(SaveCommand.java:30)
 [12:47:24 WARN]:        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:199)
 [12:47:24 WARN]:        at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:547)
 [12:47:24 WARN]:        at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchServerCommand(CraftServer.java:534)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.DedicatedServer.aw(DedicatedServer.java:309)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:274)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:560)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:467)
 [12:47:24 WARN]:        at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617)

I have now disabled both those worlds and everything seems to run fine. I will have to find out what exactly is doing this and then I can re-enable these worlds.