MySQL Bin Files Eating Lots of Disk Space

by on December 16, 2008 · 11 comments· LAST UPDATED December 18, 2008

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Q. I get a large amount of bin files in the MySQL data directory called "server-bin.n" or mysql-bin.00000n, where n is a number that increments. What is MySQL Binary Log? How do I stop these files being created?

A. Usually /var/lib/mysql stores the binary log files. The binary log contains all statements that update data or potentially could have updated it. For example, a DELETE or UPDATE which matched no rows. Statements are stored in the form of events that describe the modifications. The binary log also contains information about how long each statement took that updated data.

The purpose of MySQL Binary Log

The binary log has two important purposes:

  • Data Recovery : It may be used for data recovery operations. After a backup file has been restored, the events in the binary log that were recorded after the backup was made are re-executed. These events bring databases up to date from the point of the backup.
  • High availability / replication : The binary log is used on master replication servers as a record of the statements to be sent to slave servers. The master server sends the events contained in its binary log to its slaves, which execute those events to make the same data changes that were made on the master.

Disable MySQL binlogging

If you are not replicating, you can disable binlogging by changing your my.ini or my.cnf file. Open your my.ini or /etc/my.cnf (/etc/mysql/my.cnf), enter:
# vi /etc/my.cnf
Find a line that reads "log_bin" and remove or comment it as follows:

#log_bin                        = /var/log/mysql/mysql-bin.log

You also need to remove or comment following lines:

#expire_logs_days        = 10
#max_binlog_size         = 100M

Close and save the file. Finally, restart mysql server:
# service mysql restart

Purge Master Logs

If you ARE replicating, then you need to periodically RESET MASTER or PURGE MASTER LOGS to clear out the old logs as those files are necessary for the proper operation of replication. Use following command to purge master logs:

$ mysql -u root -p 'MyPassword' -e "PURGE BINARY LOGS TO 'mysql-bin.03';"

OR

$ mysql -u root -p 'MyPassword' -e "PURGE BINARY LOGS BEFORE '2008-12-15 10:06:06';"

Suggested readings:

MySQL Manual - The binary logs

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{ 11 comments… read them below or add one }

1 Amr Hamdy December 17, 2008 at 6:44 pm

If you are using
expire_logs_days = 10
max_binlog_size = 100M
You will not need to do purge logs manually .. logs older than 10 days will be purged automatically by mysql server …

Thanks

Reply

2 NiTRo December 24, 2008 at 4:30 pm

Amr Hamdy,
you’re right but if you disable log_bin, you must purge manually.

Thanks for this post.

Reply

3 Johny June 26, 2009 at 7:47 am

Hi, thanks for the tips

does it works on innodb too ?

Reply

4 Steve Stringer April 22, 2010 at 9:33 am

Awesome tip. My logs were taking up 40 Gigs on my dev server and I had no idea.

Thanks!

Reply

5 Music01 May 6, 2010 at 7:46 pm

#!/bin/bash
CURRENT_LOGFILE=$(/usr/bin/mysql -u root -p -S -e "SHOW SLAVE STATUS\G" | awk '$1 == "Master_Log_File:" {print $2}')
echo "Purging Master Logs before ${CURRENT_LOGFILE}"
/usr/bin/mysql -uroot -p -h -P -e "PURGE MASTER LOGS TO '${CURRENT_LOGFILE}'"
echo "Purging Slave Logs before Current Log'"
/usr/bin/mysql -uroot -p -h -S -e "purge binary logs before now();"
exit $?

Reply

6 Aaron February 23, 2011 at 4:43 pm

Hi, just a small correction:
About the High availability / replication section. It states that the Master sends the binary logs to the slave. However, it’s actually the slave that pulls the log/data from the master.

“Each slave that connects to the master requests a copy of the binary log. That is, it pulls the data from the master, rather than the master pushing the data to the slave”
Source: http://dev.mysql.com/doc/refman/5.0/en/replication-implementation.html

Reply

7 cangshubao October 13, 2011 at 10:46 am

hi

could you tell me how to perform the data recovery operations by these files
thanks

Reply

8 Katie @ StylishandTrendy July 11, 2012 at 12:08 pm

Alternatively, you can try this mysql> PURGE BINARY LOGS BEFORE DATE_SUB( NOW( ), INTERVAL 7 DAY);

This deletes all logs older than 7 days.

Reply

9 Katie @ StylishandTrendy July 11, 2012 at 12:09 pm

Alternatively we can simply use this command

mysql> PURGE BINARY LOGS BEFORE DATE_SUB( NOW( ), INTERVAL 7 DAY);

It deletes all old logs older than 7 days.

Reply

10 linux7802 August 7, 2012 at 10:59 am

nice information ….

Reply

11 Gopalji varshneya August 31, 2013 at 11:57 am

PURGE BINARY LOGS BEFORE now()

Reply

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