Are mysql bins safe to remove?

Question

They are taking up too much space:

/var/lib/mysql/jiaoyou-slow.log: 53M
/var/lib/mysql/mysql-bin.000005: 68M
/var/lib/mysql/mysql-bin.000003: 1.1G
/var/lib/mysql/mysql-bin.000007: 34M
/var/lib/mysql/mysql-bin.000004: 225M

Answer 1

There are a few reasons to use binary logging. In order of importance:

1. Replication -- Slaves suck content from the master's binary log.
2. Greater backup granularity -- Replay logs over a prior backup point.
3. Query logging -- More efficient than the general query log for those occasional "what write query ran?" moments.

So there are three things to check before you delete any binary logs:

1. Do you have any replication slaves and are they up to date?
   • If you delete a binary log before the slave has had a chance to pull it into it's relay log then it will be unable to proceed with replication. Also there can be freak instances where you may need to delete the relay log and spool again from the master.
2. Are your backups in check?
3. Will you need to review any queries that have been executed over that logging period?

If you are happy with the answers to all of those then go ahead and delete them with the PURGE command as noted by RageZ. Absolutely don't delete them by hand because MySQL likes to keep track of them. You can either use the syntax TO to specify a filename or BEFORE to specify a date. You can see which file MySQL currently has open with SHOW MASTER STATUS.

A much better approach, as kedar notes, is to use expire_logs_days. This will automatically perform the action of purging any binary logs that are older than N days.

Answer 2

no, you not should delete them by hand there is a command to remove them, if delete them mysql would crash. the command is:

PURGE BINARY LOGS TO 'mysql-bin.010';

see here for more information.

Answer 3

you may also use expire_logs_days http://dev.mysql.com/doc/refman/5.0/en/purge-binary-logs.html

Answer 4

Its safe to remove the slow query log (/var/lib/mysql/jiaoyou-slow.log). To remove, you may have to shutdown mysql. But I recommend inspecting the slow query log before deleting. It gives you an idea about which queries take longer than expected to execute and you may want to optimize them sometime later.