How To Increase max_open_files for MySQL

Introduction

Sometimes MySQL needs more open files than cPanel's automatic algorithm predicts.  In those cases, you can set the limit higher manually.

Procedure

Step 1

Turn off cPanel's automatic setting of the value in Tweak Settings by following the steps in this article: Changes to MySQL configuration are reverted automatically

Step 2

Edit the file at /etc/systemd/system/mysqld.service.d/limits.conf with the following command:

systemctl edit mysqld

Step 3

Tell systemd to re-read the config files to apply the changes with the following command:

systemctl daemon-reload

Step 4

Restart MySQL with the following command:

/scripts/restartsrv_mysql

Resources

• MySQL 8 Documentation on Using Systemd