Once it is located, you can run a command to restart the software. Note
that the scripts might have slightly different names, like apache, apache2
or mysql.
root@server# /etc/init.d/httpd restart
root@server# /etc/init.d/mysqld restartHopefully, it will say something like Stopping... Starting... Started.
Your websites will start behaving normally again!
Permanent Fix
As above, check the log files, especially the Apache error logs. Sometimes
these are all in one place, but usually each website on the server has its
own error log. You could look through the ones that were busiest around
the time of the crash. Or else you could have a misconfiguration, a
programming bug or a security breach, so it could happen again until you
identify and address the cause.
Becoming a Super-User
Most of the fixes above require special permissions. For example, you (i.e.
the user you have logged in as) will be able to kill or restart processes only
if you started them. This can happen on shared servers but is unlikely on
dedicated servers, where you will see a lot of permission denied
messages. So, to run those commands, you will need to become the
server’s super-user, usually known as “root.” I’ve left this for last because
it’s dangerous. You can do a lot of irreversible damage as root. Please don’t
remove or restart anything unless you’re sure about it, and don’t leave your
computer unattended.