When we use mysql or other data, we always encounter that the database occupies a lot of disk space, resulting in insufficient disk space, which leads to other problems (for example: the database cannot be started after restarting; the database cannot write data, etc.). To solve this problem, the method is to delete some unnecessary files in the database. The binlog log that takes up a lot of disk space in the mysql database is generally the binlog log, because it records the changes in the data in the database, so it will continue to grow larger with the accumulation of time. Time or location based recovery and error handling.
The following is a solution to solve the problem that the mysql database occupies a lot of disk space.
 Check whether the binlog log of mysql is too large
Due to the installation version or installation method of mysql, the location or log name of the binlog log is different. You need to check the log size according to your own situation. (The usual location is:
cd /mysql/data/ du -sh *
The picture above shows the location of my actual
binlog. As can be seen from the above figure, it is true that the
binlog of mysql is too large and takes up disk space.
【2】Delete the log file
There are two cases
Case 1: The database doesn't have master and slave
Execute in the database:
This command can also be used if the database has master-slave, but it is easy to cause master-slave synchronization failure.
Case 2: The database has master and slave
Check which file is the binlog being used by the master library and each slave library
show master status;
show slave status\G;
Delete all binary logs in the log index before the specified log sequence number or date
purge master logs to 'mysql-bin.000003'; purge master logs before '2018-08-29 12:00:00';
Notice: Don not delete binlog in use. The time and file name cannot be wrongly written (depending on your actual situation)
 Difference between reset master and purge binary logs
reset master: delete all binglog log files, empty the log index file, and start over with a new log file.
purge binary logs: delete logs based on a point in time
View the current log retention days
show variables like 'expire_logs_days';
Set the binlog to keep only 3 days
(Temporarily, restarting the mysql parameter will fail)
set global expire_logs_days = 3;
(Permanent, added in
my.cnf, it will take effect after restart),
expire_logs_days = 3
Notice: The default value is 0, which means "Auto delete is not enabled". The expiration time should be set appropriately
If master-slave is used, this operation is prohibited
1 Comment out the following in
2 restart mysql
systemctl restart mysql (centos 7) /etc/init.d/mysql restart (centos 6)