Upgrading Ram, Clearing server cache?

I currently got my own VPS for my server and everything runs great on it. Lately been started to get a bit laggy at times but i upgraded my ram.

I am getting this message
[WARNING] Can't keep up. Did the system time change, or is the server overloaded.

I figured it cause I had just 1gb ram, but i upgraded to 2gb now.

At first i used in my .bat

Code:

@ECHO OFF
IF /I "%PROCESSOR_ARCHITECTURE:~-2%"=="64" "%ProgramFiles(x86)%\Java\jre6\bin\java.exe" -Xms1024M -Xmx1024M -jar "%~dp0craftbukkit.jar"
IF /I "%PROCESSOR_ARCHITECTURE:~-2%"=="86" java -Xms1024M -Xmx1024M -jar "%~dp0craftbukkit.jar"
PAUSE

to boot up my server, and works fine i figure i change it from 1024 to 2048 for upgrade, but i need a error saying cant create the data? Any ideas?

How would i be able to clear the server cache? Someone mentioned something but havnt been able to find a way to. Still REALLY noobish at this.

Thanks.

 

who is your server provider?

 

Im using a go daddy VPS
--- merged: Feb 17, 2011 7:27 PM ---
im using a 2008 server if that helps.

 

How much total memory do you have on the vps?

 

2gb ram