Fix MySQL errno 24 - too many files open

You might notice that your database applications aren't working in conjunction with this error. errno 24, which you might have seen in your log file, or in the frontend of an application you are using, means that MySQL has detected that there are too many files open.

In order to fix the errno: 24 problem, and to get your MySQL databases running again, is to change the limit of the max allowed open files. 

On my Debian system, all I did was edit /etc/mysql/my.conf so that it contains the following line:

open_files_limit = 100000

Then I restarted MySQL, and all of my databases were up and running again.

More information on errno: 24 and more possible solutions can be found at:

• http://askubuntu.com/questions/288471/mysql-cant-open-files-after-updating-server-errno-24
• http://serverfault.com/questions/440878/changing-open-files-limit-in-mysql-5-5
• https://stackoverflow.com/questions/11390213/1016-cant-open-file-database-name-sql-38f-36aa-frm-errno-24
• http://kb.parallels.com/en/118742
• https://dev.mysql.com/doc/refman/5.5/en/server-options.html#c12634