我的操作系统是Redhat8。目前我安装了Mysql，版本是"Mysql版本8.0.13，适用于x86_64上的Linux(源发行版(">
我使用命令"sudo yum-install mysql，mysql-server">
但当我想启动mysql服务时，我会遇到错误。我一直在寻找解决方案，但仍然不知道如何解决。
有人能帮我看看吗？
#--------------------------------------------------------------------------------------------------------
[yliu@rhlab1 ~]$ sudo 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.
# --------------------------------------------------------------------------------------------
[yliu@rhlab1 ~]$ sudo systemctl status mysqld
● mysqld.service - MySQL 8.0 database server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Wed 2020-02-19 12:12:15 AST; 15s ago
Process: 13080 ExecStopPost=/usr/libexec/mysql-wait-stop (code=exited, status=0/SUCCESS)
Process: 13052 ExecStart=/usr/libexec/mysqld --basedir=/usr (code=exited, status=1/FAILURE)
Process: 13015 ExecStartPre=/usr/libexec/mysql-prepare-db-dir mysqld.service (code=exited, status=0/SUCCESS)
Process: 12991 ExecStartPre=/usr/libexec/mysql-check-socket (code=exited, status=0/SUCCESS)
Main PID: 13052 (code=exited, status=1/FAILURE)
Status: "SERVER_BOOTING"
Error: 2 (No such file or directory)
Feb 19 12:12:12 systemd[1]: Starting MySQL 8.0 database server...
Feb 19 12:12:15 systemd[1]: mysqld.service: Main process exited, code=exited, status=1/FAILURE
Feb 19 12:12:15 systemd[1]: mysqld.service: Failed with result 'exit-code'.
Feb 19 12:12:15 systemd[1]: Failed to start MySQL 8.0 database server.
# ----------------------------------------------------------------------------------------
[yliu@rhlab1 ~]$ sudo cat /var/log/mysql/mysqld.log | nl | tail -n 10
38 2020-02-19T15:48:25.492390Z 0 [System] [MY-010910] [Server] /usr/libexec/mysqld: Shutdown complete (mysqld 8.0.13) Source distribution.
39 2020-02-19T15:48:25.492468Z 0 [ERROR] [MY-010065] [Server] Failed to shutdown components infrastructure.
40 2020-02-19T16:12:13.332724Z 0 [System] [MY-010116] [Server] /usr/libexec/mysqld (mysqld 8.0.13) starting as process 13052
41 2020-02-19T16:12:13.585641Z 1 [ERROR] [MY-010781] [Server] Found ./mysql/index_stats.frm file in mysql schema. DD will create .ibd file with same name. Please rename table and start upgrade process again.
42 2020-02-19T16:12:13.585666Z 1 [ERROR] [MY-010336] [Server] Found .frm file with same name as one of the Dictionary Tables.
43 2020-02-19T16:12:13.585833Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
44 2020-02-19T16:12:13.585871Z 0 [ERROR] [MY-013236] [Server] Newly created data directory /var/lib/mysql/ is unusable. You can safely remove it.
45 2020-02-19T16:12:13.585881Z 0 [ERROR] [MY-010119] [Server] Aborting
46 2020-02-19T16:12:15.000469Z 0 [System] [MY-010910] [Server] /usr/libexec/mysqld: Shutdown complete (mysqld 8.0.13) Source distribution.
47 2020-02-19T16:12:15.000550Z 0 [ERROR] [MY-010065] [Server] Failed to shutdown components infrastructure.
我的/etc/My.cnf.d/mysql-server.cnf信息为：
[yliu@rhlab1 ~]$ sudo cat /etc/my.cnf.d/mysql-server.cnf
#
# This group are read by MySQL server.
# Use it for options that only the server (but not clients) should see
#
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/en/server-configuration-defaults.html
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mysqld according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
我解决了这个问题，希望它对遇到同样问题的每个人都有帮助。
基于日志：
41 2020-02-19T16:12:13.585641Z 1 [ERROR] [MY-010781] [Server] Found ./mysql/index_stats.frm file in mysql schema. DD will create .ibd file with same name. Please rename table and start upgrade process again.
42 2020-02-19T16:12:13.585666Z 1 [ERROR] [MY-010336] [Server] Found .frm file with same name as one of the Dictionary Tables.
43 2020-02-19T16:12:13.585833Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
44 2020-02-19T16:12:13.585871Z 0 [ERROR] [MY-013236] [Server] Newly created data directory /var/lib/mysql/ is unusable. You can safely remove it.
因此，我们可以删除/var/lib/mysql下的所有文件/然后确保mysql文件的所有者和组是mysql。
(Django) [yliu@rhlab1 ops]$ sudo ls -al /var/lib/ | grep mysql
drwxr-xr-x. 7 mysql mysql 4096 Feb 24 10:16 mysql
然后你可以再次启动mysqld
sudo systemctl start mysqld