MySQL startup error: innodb: operating system error number 13 in a file operation

start-up mysql Report errors ：

[[email protected] ~]# systemctl start mysqld
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

There are three ways to view error information ：

1. systemctl status mysqld.service

[[email protected] ~]# systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since  6、 ... and  2020-03-14 03:55:06 CST; 14s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 73992 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=1/FAILURE)
  Process: 73975 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 72217 (code=exited, status=0/SUCCESS)

3 month  14 03:55:06 localhost.localdomain systemd[1]: Failed to start MySQL Server.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service failed.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Stopped MySQL Server.
3 month  14 03:55:06 localhost.localdomain systemd[1]: start request repeated too quickly for mysqld.service
3 month  14 03:55:06 localhost.localdomain systemd[1]: Failed to start MySQL Server.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service failed.

2. journalctl -xe

[[email protected] ~]# journalctl -xe
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has failed.
-- 
-- The result is failed.
3 month  14 03:55:04 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
3 month  14 03:55:04 localhost.localdomain systemd[1]: mysqld.service failed.
3 month  14 03:55:05 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
3 month  14 03:55:05 localhost.localdomain systemd[1]: Stopped MySQL Server.
-- Subject: Unit mysqld.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has finished shutting down.
3 month  14 03:55:05 localhost.localdomain systemd[1]: Starting MySQL Server...
-- Subject: Unit mysqld.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has begun starting up.
3 month  14 03:55:06 localhost.localdomain mysqld[73992]: Initialization of mysqld failed: 0
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service: control process exited, code=exited status=1
3 month  14 03:55:06 localhost.localdomain systemd[1]: Failed to start MySQL Server.
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has failed.
-- 
-- The result is failed.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service failed.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Stopped MySQL Server.
-- Subject: Unit mysqld.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has finished shutting down.
3 month  14 03:55:06 localhost.localdomain systemd[1]: start request repeated too quickly for mysqld.service
3 month  14 03:55:06 localhost.localdomain systemd[1]: Failed to start MySQL Server.
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysqld.service has failed.
-- 
-- The result is failed.
3 month  14 03:55:06 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
3 month  14 03:55:06 localhost.localdomain systemd[1]: mysqld.service failed.

misarrangement ：

After looking at the log, you can see ERROR Information , What I don't understand can be translated , Easy to understand , Looking for useful information . Log path can be accessed through /etc/my.cnf The file to view

[ERROR] InnoDB: Operating system error number 13 in a file operation.
[ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.
[ERROR] InnoDB: os_file_get_status() failed on './ibdata1'. Can't determine file permissions
[ERROR] InnoDB: Plugin initialization aborted with error Generic error
[ERROR] Plugin 'InnoDB' init function returned error.
[ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
[ERROR] Failed to initialize builtin plugins.
[ERROR] Aborting
                    ↓↓↓↓↓↓
[ error ] InnoDB: Operating system error number in file operation 13.
[ error ] InnoDB: The error means mysqld No access to the directory .
[ error ] InnoDB: os_file_get_status() Failed on ./ibdata1. Unable to determine file permissions 
[ error ] InnoDB: Plug in initialization aborted , There is a general error 
[ error ] plug-in unit “InnoDB” The initialization function returned an error .
[ error ] plug-in unit “InnoDB” Failed to register as storage engine .
[ error ] Failed to initialize the built-in plug-in .
[ error ] suspend 

Solution ：

[[email protected] ~]# getenforce    // see selinux state 
Enforcing
[[email protected] ~]# setenforce 0    // Temporarily Closed selinux, Failure after restart 

[[email protected] ~]# getenforce
Permissive
[[email protected] ~]# systemctl start mysqld     // start-up mysql Service successfully 
[[email protected] ~]# ss -antulp | grep :3306
tcp    LISTEN     0      80     [::]:3306               [::]:*                   users:(("mysqld",pid=74057,fd=17))

Permanent ban selinux

[[email protected] ~]# cat /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

Backup configuration files

[[email protected] ~]# cp -r /etc/selinux/config /etc/selinux/config.bak

[[email protected] ~]# sed -i 's/SELINUX=enforcing/\SELINUX=disabled/' /etc/selinux/config

[[email protected] ~]# cat /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted