centos 8 启动mysql失败 之 File operation call: 'open'.

[root@localhost ~]# mysqld --defaults-file=/etc/my.cnf --user=mysql &
[1] 2127
[root@localhost ~]# 210418 19:26:30 [Note] Plugin 'FEDERATED' is disabled.
210418 19:26:30  InnoDB: Initializing buffer pool, size = 8.0M
210418 19:26:30  InnoDB: Completed initialization of buffer pool
210418 19:26:30  InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name ./ibdata1
InnoDB: File operation call: 'open'.
InnoDB: Cannot continue operation.

考虑到mysql服务使用mysql用户启动的，首先增加mysql用户，

useradd -r mysql

修改目录权限：

cd /var/lib/mysql
chown -R mysql.mysql *

再次启动即可：

[root@localhost mysql]# mysqld --defaults-file=/etc/my.cnf --user=mysql &
[1] 2286
[root@localhost mysql]# 210418 19:31:06 [Note] Plugin 'FEDERATED' is disabled.
210418 19:31:06  InnoDB: Initializing buffer pool, size = 8.0M
210418 19:31:06  InnoDB: Completed initialization of buffer pool
210418 19:31:06  InnoDB: Started; log sequence number 0 341206
210418 19:31:06 [Note] Event Scheduler: Loaded 0 events
210418 19:31:06 [Note] mysqld: ready for connections.
Version: '5.1.73'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Server (GPL)

至此启动成功