Out of memory (OOM) is a state of computer operation (often undesired) where no additional memory can be allocated for use by programs or the operating system. Such a system will be unable to load any additional programs and since many programs may load additional data into memory during execution, these will cease to function correctly. This occurs because all available memory, including disk swap space, has been allocated. The typical OOM case in modern computers happens when the operating system is unable to create any more virtual memory, because all of its potential backing devices have been filled.

Operating systems such as Linux will attempt to recover from this type of OOM condition by terminating a low-priority process, a mechanism known as the OOM Killer, which is still vulnerable in some cases to memory leak. The OOM-Killer may terminate processes that you use frequently, such as Apache, SSH or MySQL - it simply selects processes at random (low priority processes) in an attempt to keep the machine operational.

If you find that your server becomes unresponsive there are a number of tools available to you through your WebDady control panel. On the virtual machine overview page, an emergency console is available to allow you to connect in through a KVM style java applet to view the contents of the server console, even when the machine is unreachable from the internet, the console allows you to identify any onscreen errors and to monitor the booting/rebooting progress of your cloud server. If a server is completely unresponsive you can Reboot the server through the virtual machine overview page, once initiated you can use the emergency console to monitor the booting progress of the machine. When clicking reboot, start, or stop please allow 5-10 minutes for the machine to fully restart and for the necessary services installed to start normally.