innodb_log_files_in_group调整方法

官方文档：

 innodb_log_files_in_group

Command-Line Format	--innodb_log_files_in_group=#
Option-File Format	innodb_log_files_in_group
Option Sets Variable	Yes, innodb_log_files_in_group
Variable Name	innodb_log_files_in_group
Variable Scope	Global
Dynamic Variable	No
	Permitted Values
	Type	numeric
	Default	2
	Range	2-100

The number of log files in the log group. InnoDB writes to the files in a circular fashion. The default (and recommended) value is 2.

 

当我直接修改my.cnf将该参数改为3的时候

重启mysql，报错，innodb引擎无法挂载

110124 14:06:23  InnoDB: Log file ./ib_logfile2 did not exist: new to be created
110124 14:06:23 [ERROR] Plugin 'InnoDB' init function returned error.
110124 14:06:23 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.

 

 

 

 

Saver 说 (14:29):
*innodb_log_files_in_group 这个参数在初始化系统之后就不能调整了？
Popgo 说 (14:31):
*可以的
*你要先把原来的log备份下
Saver 说 (14:31):
*然后删了？
Popgo 说 (14:32):
*不是啊
Saver 说 (14:32):
*那咋搞
Popgo 说 (14:32):
*把原来的log文件备份，把innodb_log_files_in_group变成你需要的。让数据重新生成log文件

 

调整方式：

1.停止服务

 1036  service mysqld stop
2.移走当前的日志文件 
 1038  mkdir bak
 1039  cd bak
 1040  cd ..
 1041  mv ib_logfile* ./bak/
3.在my.cnf中修改参数数值

4.启动服务
 1043  service mysqld start

 

系统处理日志

110124 14:44:55 mysqld_safe Starting mysqld daemon with databases from /data/mysql
110124 14:44:55  InnoDB: Log file ./ib_logfile0 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile0 size to 512 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Progress in MB: 100 200 300 400 500
110124 14:45:00  InnoDB: Log file ./ib_logfile1 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile1 size to 512 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Progress in MB: 100 200 300 400 500
110124 14:45:05  InnoDB: Log file ./ib_logfile2 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile2 size to 512 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Progress in MB: 100 200 300 400 500
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
110124 14:45:10  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: Last MySQL binlog file position 0 793029012, file name ./mysql-bin.000048
110124 14:45:12  InnoDB: Started; log sequence number 136 3284391948