this will help you http://adminlinux.blogspot.com/2009/09/mysql-log-file-rotation.html
On Fri, Aug 12, 2011 at 9:43 AM, Paul DuBois <paul.dub...@oracle.com> wrote: > > On Aug 11, 2011, at 2:30 PM, Keith Murphy wrote: > > > Hey everyone, > > > > I have run across something that has me stumped. I have some systems that > > have very large error logs because we haven't moved from statement-based > to > > mixed-based replication yet so they get a lot of warnings logged. I need > to > > rotate the error logs and have started looking at it doing so. > > > > The problem is that on one system a normal course of action works > perfectly, > > but on anther it does not. And these systems were installed from the same > > RPM packages (5.1.50 -- downloaded from the MySQL website). > > > > Here is what I do: > > > > > > log in with mysql client and 'flush logs' OR mysqladmin --flush-log > > > > It should rename the old log file to mysqld.log-old and start a new > > mysqld.log file. > > > > On one system it works perfectly > > > > On the other...nothing. > > > > I tried moving the error log (mv /var/log/mysqld/mysqld.log > > /var/log/mysqld.log.old) and then issuing the flush logs command...it > stays > > writing to the "old" file and never makes a new one. > > > > If I were to restart mysqld it would solve the problem but this is a > > production system and that isn't very practical. > > > > These systems are very similar. my.cnfs have been checked for > differences. I > > searched the interwebs and specifically bugs.mysql.com for something > > similar. Not finding anything. > > > > I would appreciate any ideas! > > > There was a change to log flushing that affects the error log in 5.1.51/ > 5.5.7. > It might be the cause of what you're seeing. > > http://dev.mysql.com/doc/refman/5.1/en/news-5-1-51.html > http://dev.mysql.com/doc/refman/5.5/en/news-5-5-7.html > > " > Incompatible Change: Previously, if you flushed the logs using FLUSH LOGS > or mysqladmin flush-logs andmysqld was writing the error log to a file (for > example, if it was started with the --log-error option), it renamed the > current log file with the suffix -old, then created a new empty log file. > This had the problem that a second log-flushing operation thus caused the > original error log file to be lost unless you saved it under a different > name. For example, you could use the following commands to save the file: > > shell> mysqladmin flush-logs > > shell> mv host_name.err-old backup-directory > > To avoid the preceding file-loss problem, renaming no longer occurs. The > server merely closes and reopens the log file. To rename the file, you can > do so manually before flushing. Then flushing the logs reopens a new file > with the original file name. For example, you can rename the file and create > a new one using the following commands: > > shell> mv host_name.err host_name.err-old > > shell> mysqladmin flush-logs > > shell> mv host_name.err-old backup-directory > > (Bug #29751) > > See also Bug #56821. > " > -- > Paul DuBois > Oracle Corporation / MySQL Documentation Team > Madison, Wisconsin, USA > www.mysql.com > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/mysql?unsub=aim.prab...@gmail.com > > -- Best Regards, Prabhat Kumar MySQL DBA My Blog: http://adminlinux.blogspot.com My LinkedIn: http://www.linkedin.com/in/profileprabhat
