一套线上环境的REDO日志的大小和格式设置的不合理，需要将日志大小修改成2G，个数改为5个。

# 修改参数文件

# vi /etc/my_56.cnf

innodb_log_file_size = 2G

innodb_log_files_in_group = 5

# 重启数据库

# 启动的时候，查看错误日志，可以看到重新初始化了REDO日志

2018-05-28 09:40:54 25439 [Note] Plugin 'FEDERATED' is disabled.

2018-05-28 09:40:54 25439 [Note] InnoDB: Using atomics to ref count buffer pool pages

2018-05-28 09:40:54 25439 [Note] InnoDB: The InnoDB memory heap is disabled

2018-05-28 09:40:54 25439 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

2018-05-28 09:40:54 25439 [Note] InnoDB: Memory barrier is not used

2018-05-28 09:40:54 25439 [Note] InnoDB: Compressed tables use zlib 1.2.3

2018-05-28 09:40:54 25439 [Note] InnoDB: Using Linux native AIO

2018-05-28 09:40:54 25439 [Note] InnoDB: Using CPU crc32 instructions

2018-05-28 09:40:54 25439 [Note] InnoDB: Initializing buffer pool, size = 1.0G

2018-05-28 09:40:55 25439 [Note] InnoDB: Completed initialization of buffer pool

2018-05-28 09:40:55 25439 [Note] InnoDB: Highest supported file format is Barracuda.

2018-05-28 09:40:55 25439 [Warning] InnoDB: Resizing redo log from 2*3072 to 5*131072 pages, LSN=19620839567

2018-05-28 09:40:55 25439 [Warning] InnoDB: Starting to delete and rewrite log files.

2018-05-28 09:40:55 25439 [Note] InnoDB: Setting log file ./ib_logfile101 size to 2048 MB

InnoDB: Progress in MB: 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

2018-05-28 09:41:06 25439 [Note] InnoDB: Setting log file ./ib_logfile1 size to 2048 MB

InnoDB: Progress in MB: 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

2018-05-28 09:41:16 25439 [Note] InnoDB: Setting log file ./ib_logfile2 size to 2048 MB

InnoDB: Progress in MB: 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

2018-05-28 09:41:26 25439 [Note] InnoDB: Setting log file ./ib_logfile3 size to 2048 MB

InnoDB: Progress in MB: 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

2018-05-28 09:41:36 25439 [Note] InnoDB: Setting log file ./ib_logfile4 size to 2048 MB

InnoDB: Progress in MB: 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

2018-05-28 09:41:46 25439 [Note] InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0

2018-05-28 09:41:46 25439 [Warning] InnoDB: New log files created, LSN=19620839567

2018-05-28 09:41:46 25439 [Note] InnoDB: 128 rollback segment(s) are active.

2018-05-28 09:41:46 25439 [Note] InnoDB: Waiting for purge to start

2018-05-28 09:41:46 25439 [Note] InnoDB: 5.6.39 started; log sequence number 19620839567

2018-05-28 09:41:46 25439 [Note] Server hostname (bind-address): '*'; port: 3306

2018-05-28 09:41:46 25439 [Note] IPv6 is available.

# 启动成功后，查看REDO日志的大小

mysql> show global variables like '%innodb_log_file_size%';

+----------------------+------------+

| Variable_name | Value |

+----------------------+------------+

| innodb_log_file_size | 2147483648 |

+----------------------+------------+

1 row in set (0.01 sec)

mysql> show global variables like '%innodb_log_files_in_group%';

+---------------------------+-------+

| Variable_name | Value |

+---------------------------+-------+

| innodb_log_files_in_group | 5 |

+---------------------------+-------+

1 row in set (0.01 sec)