[WARNING] Cant keep up! did server time change

i keep getting the [warning] cant keep up! did system time change or is the server overloaded, message on my server console, and i'm not sure what is causing it, i have poked around seen a few people saying some specific mods doing it or some people running on slow hardware, but thats not the case in this instance, i'm only running 1 mod (runecraft) and only have 4 people on the server, the server is a dedicated server running 3 opteron 6 cores, 64gb of ram and 6 150gig SAS drives in a raid 5 config, no one is experiencing any lag on the server, its just popping up the message, what could be causing this, also i have assigned 32gb of memory to bukkit and have never seen the cpu go over 7% usage or the cpu temp go over 23c so its not an issue there, it only started doing this earlier today, iv restarted it a few times but it still does it.

 

My servers always experience this (most of the time), but I choose to ignore as it doesn't affect the gameplay. Therefore I just turn off the warnings, to stop the spam.

If your server is 'BUKKIT' which I presume it is then follow these steps.

1) Open the file 'bukkit.yml'
2) Change the 'Warn-On-Overload: true' to 'Warn-On-Overload: false'
3) Save the file and restart the server

 

thanks

 

Allocate more memory to craftbukkit.

 

Do /gc
Post a screenshot of the output