The reason for writing this article isCentos 7.xEnvironmental InstallationMySQLSometimes I met with a problem.Centos 6.xEnvironmental InstallationMySQLIn/etc/security/limits.confFile pairs open filesnofileRestriction, restartMySQLIt will take effect afterwards, but it will take effect afterwards.Centos 7.xThe environment is useless.
Analytical findings/etc/security/limits.confIt only works for PAM login users, but if it passes throughsystemdStart the service. This configuration file does not work. For systems-initiated services, priority (the latter overrides the former) plays a role in:
- /etc/systemd/system.conf Setting global default values for system-level services（PSThe system needs to be restarted to take effect, such as:
% vi /etc/systemd/system.conf ... DefaultLimitNOFILE=50000 ...
- Services themselves, such asmysqlProcess:
% vi /usr/lib/systemd/system/mysqld.service [Service] ... LimitNOFILE = 20000 ... % systemctl deamon-reload % systemctl restart mysqld
% cat /proc/13010/limits Limit Soft Limit Hard Limit Units Max open files 20000 20000 files ...
Be carefulThe above is just for system-level services, even for usesystemctl start/stopManagement services, and forsystemctl –userManaged user-level services（PSVery rarely used and requires special configuration), environment variables, orlimitsLimitations are limited by the following documents:
- ~/.config/systemd/user.confForHOMEUsers can configure this directory again.
- /etc/systemd/user.confUser-level default configuration;
- /etc/systemd/system/[email protected]/Effective for all user-level management services;
- /etc/systemd/system/[email protected]<uid>.service.dEffective for specific users;