This has also happened to me on many occasions. I have a Kubuntu 9.04 server at the office that has 24GB of main memory, so there is no swap space defined. When an application goes haywire and takes all the main memory (e.g. VMWare), the offending process is never terminated, the mouse pointer locks up, and all attempts at a remote SSH session fail--the server has to be forcibly restarted.
This has also happened to me on many occasions. I have a Kubuntu 9.04 server at the office that has 24GB of main memory, so there is no swap space defined. When an application goes haywire and takes all the main memory (e.g. VMWare), the offending process is never terminated, the mouse pointer locks up, and all attempts at a remote SSH session fail--the server has to be forcibly restarted.
This is a critical bug!