I ran across a resource that said when you get the error The server quit without updating PID file that you should move the my.cnf file out of the way and restart MySQL.
That is just NOT the correct step to solving a problem. What about all the settings that you have in the MySQL file? If you are running a MySQL server correctly, then you will have very important variables set in that my.cnf file.
Consider this, if someone you worked with truncated a table, would you react by removing the privileges of everyone that has access to the database for a unknown amount of time or would you, instead, adjust and or remove the offending command from the offending user's privileges as well as talking with them about the error and the problems surrounding it? The same goes for moving the my.cnf file. Why remove everything when the problem is targeted?
You need to look at your error log file, it will tell you the problem. You or someone else could have edited the my.cnf file recently with an improper variable or possibly left a typo behind in the file. Moving the my.cnf does not fix the real problem; it just ignores the real problem.
The best tool available for MySQL is the error log and what it can tell you. Learn to use it and not ignore it.
To put it simply: The server quit without updating PID file is equivalent to MySQL could not start because of an error that has been noted in the error log.
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