正常使用数据库的过程出现错误
查阅 官方手册得知,出现错误的原因是空间不够了
使用
df命令一看,果然100%已使用了.
df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 50G 48G 0 100% /
解决办法也很简单,解除占用即可.要么把数据库的数据目录转移到其他地方并清理mysql的tmpdir参数对应路径下的空间,或者在/挂载点下删除其他不必要的文件腾出空间即可.
转移数据库目录
1.建立新的目录
一般linux系统在/home挂载点下的磁盘空间是最大的.
不妨在此建立新的mysql数据库目录
cd /home
mkdir DATA
cd DATA
mkdir mysql
mkdir tmp
在/home/DATA/目录下建立 mysql文件夹用于存放mysql数据库文件,建立tmp文件夹用于存在mysql临时文件.
2. 修改文件所有权
chown -R mysql:mysql /home/DATA
将此目录的拥有者变更为mysql用户(如果安装或启动时已经制定了mysql用户来启动mysql服务)
或者直接将此目录设置为所有人可读
chmod 777 -R /home/DATA
3.关闭数据库服务
service mysqld stop
4.移动原有数据库文件夹
建议使用cp命令,将原有文件数据保留,待更改目录正常启动之后,再做进一步处理
多个备份,有备无患
mysql默认将文件存放于/var/lib/mysql目录下
cp -r /var/lib/mysql /home/DATA
5. 修改数据库配置文件
(1) my.cnf
#vi /etc/my.cnf
在[client]下添加
socket=/home/DATA/mysql/mysql.sock
在[mysqld]下
注释之前的设置
#datadir=/var/lib/mysql
#socket=/var/lib/mysql/mysql.sock
修改为：
datadir=/home/DATA/mysql
socket=/home/DATA/mysql/mysql.sock
tmpdir=/home/DATA/tmp
(2) mysqld
#vi /etc/init.d/mysqld
注释掉之前的代码
#get_mysql_option mysqld datadir "/var/lib/mysql"
修改为：
get_mysql_option mysqld datadir "/opt/mysql"
(3) mysqld_safe
#vi /usr/bin/mysqld_safe
注释掉之前的代码
#DATADIR=/var/lib/mysql
修改为：
DATADIR=/opt/mysql
6. 启动服务
service mysqld start
若此时启动超时,在尝试进入 /etc/init.d/ 目录下 ,直接执行mysqld启动
若能启动成功则只需要将 / 挂载点下的空间清理出一部分来即可执行.
常见错误
在修改目录的过程中,主要遇到了如下错误
1 Can't start server : Bind on unix socket: Permission denied
启动失败,使用vim命令查看日志文件
vim /var/log/mysqld.log
发现内容如下
2018-01-20 11:19:16 23899 [ERROR] Can't start server : Bind on unix socket: Permission denied
2018-01-20 11:19:16 23899 [ERROR] Do you already have another mysqld server running on socket: /home/DATA/mysql.sock ?
2018-01-20 11:19:16 23899 [ERROR] Aborting
原因是mysql没有读取新目录的权限造成的,mysqld与mysql的通信是根据mysql.sock这个文件进行的.
必须保证mysql在指定目录下有读写此文件的权限
使用chmod命令修改权限后,文件解决
2 Timeout error occurred trying to start MySQL Daemon.
使用命令启动后,输出如下
Stopping mysqld: [FAILED]
Timeout error occurred trying to start MySQL Daemon.
Starting mysqld: [FAILED]
主要是由于 / 挂载点下是100%占用, mysql无法读写日志文件造成的启动超时
清理空间后,问题解决
修复升级后的数据表结构错误
数据库正常启动后
在日志中间如下字样
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_waits_summary_global_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'file_instances' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'file_summary_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'file_summary_by_instance' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'host_cache' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'mutex_instances' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'objects_summary_global_by_type' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'performance_timers' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'rwlock_instances' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'setup_actors' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'setup_consumers' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'setup_instruments' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'setup_objects' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'setup_timers' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'table_io_waits_summary_by_index_usage' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'table_io_waits_summary_by_table' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'table_lock_waits_summary_by_table' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'threads' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_current' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_history' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_history_long' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_summary_by_thread_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_summary_by_account_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_summary_by_user_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_summary_by_host_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_stages_summary_global_by_event_name' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_statements_current' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_statements_history' has the wrong structure
2018-01-20 11:43:30 32044 [ERROR] Native table 'performance_schema'.'events_statements_history_long' has the wrong structure
意思是说这些基础表的结构错误
这是由于mysql升级之后造成的问题
根据日志中提示的修复方法
/usr/bin/mysql_upgrade -u root -p
根据提示输入密码后,修复完成
Enter password:
Looking for 'mysql' as: /usr/bin/mysql
Looking for 'mysqlcheck' as: /usr/bin/mysqlcheck
Running 'mysqlcheck' with connection arguments: '--socket=/home/DATA/mysql/mysql.sock'
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck' with connection arguments: '--socket=/home/DATA/mysql/mysql.sock'
Warning: Using a password on the command line interface can be insecure.
mysql.columns_priv OK
mysql.db OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.host OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.servers OK
mysql.slow_log OK
mysql.tables_priv OK
mysql.time_zone OK
mysql.time_zone_leap_second OK
mysql.time_zone_name OK
mysql.time_zone_transition OK
mysql.time_zone_transition_type OK
mysql.user OK
Running 'mysql_fix_privilege_tables'...
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck' with connection arguments: '--socket=/home/DATA/mysql/mysql.sock'
Warning: Using a password on the command line interface can be insecure.
Running 'mysqlcheck' with connection arguments: '--socket=/home/DATA/mysql/mysql.sock'
Warning: Using a password on the command line interface can be insecure.
这样就解决了因为mysql升级而造成的表结构错误问题.