iostat 等运维命令用法

报错信息：

[root@localhost scripts]# /etc/init.d/mysqld start
Starting MySQL.. ERROR! The server quit without updating PID file (/application/mysql/localhost.localdomain.pid).
[root@localhost scripts]#
[root@localhost scripts]# cat
150506 23:12:36 mysqld_safe Starting mysqld daemon with databases from /application/mysql
/application/mysql/bin/mysqld: Table 'mysql.plugin' doesn't exist
150506 23:12:36 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
150506 23:12:36 InnoDB: The InnoDB memory heap is disabled
150506 23:12:36 InnoDB: Mutexes and rw_locks use GCC atomic builtins
150506 23:12:36 InnoDB: Compressed tables use zlib 1.2.3
150506 23:12:36 InnoDB: Initializing buffer pool, size = 128.0M
150506 23:12:36 InnoDB: Completed initialization of buffer pool
150506 23:12:36 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 48941
150506 23:12:36  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Doing recovery: scanned up to log sequence number 1595675
150506 23:12:36  InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
150506 23:12:36  InnoDB: Waiting for the background threads to start
150506 23:12:37 InnoDB: 5.5.32 started; log sequence number 1595675
150506 23:12:37 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
150506 23:12:37 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
150506 23:12:37 [Note] Server socket created on IP: '0.0.0.0'.
150506 23:12:37 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist
150506 23:12:37 mysqld_safe mysqld from pid file /application/mysql/localhost.localdomain.pid ended
[root@localhost scripts]#

解决方法：
1.查看是否有其他mysql数据库已经安装并使用了3306端口[root@localhost scripts]# ps aux|grep mysql*[root@localhost scripts]# rpm -qa|egrep mysql
2.查看 /etc/my.cnf [root@localhost application]# cat /etc/my.cnf 3.更改配置文件，添加下面的内容：[root@localhost application]# vi /etc/my.cnf [mysqld]datadir=/application/mysql/data4.然后重新启动数据库：/etc/init.d/mysqld start5.如果还不行，查看日志文件确定问题。

本文出自 “MySQL_db” 博客，请务必保留此出处http://mysqldb.blog.51cto.com/10264653/1655539