Linux Memory Usage Issues
With Linux, you must keep an eye on the system health to ensure that your hard drive space and memory do not get eaten up. If you exhaust your limit, you end up with issues like websites that cannot be viewed and the inability to login to GUIs like Web Host Manager and Cpanel.
When you do run out of memory and attempt to login to a control panel like Web Host Manager, you could see the an error message that is displayed below.
Internal Server Error 500 No response from subprocess (whostmgr (cpanel)) with exit signal: 0
Running Out of Memory
If you run out of memory, you need to login to your host with SSH and stop or kill some services; like mySQL. If you use a service like Web Host Manager and Cpanel, you may need to reboot the cpanel service to have access to your control panels.
To restart Cpanel,
Once you have been able to login to Web Host Manager, you can do a graceful system reboot and hopefully your memory slide back into a usable level.
To see how much memory you have available, run the following command in the shell.