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I would like to know where will my error logged for mysql server. As of now I just see one log that is in /var/log/mysqld.log. I saw some have .err files too am I missing something here? What would the ib_logfile contain will they contain those errors too? But we cant view them right?

RolandoMySQLDBA
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newbie14
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1 Answers1

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The log buffer writes redo log information to ib_logfile0 and ib_logfile1 for transactional purposes only. There is nothing text readable within those files.

The file /var/log/mysqld.log is the main error-logging mechanism built in mysql. Anything additional would probably be in /var/log/messages.

RolandoMySQLDBA
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  • I read your answer here http://dba.stackexchange.com/questions/1261/how-to-safely-change-mysql-innodb-variable-innodb-log-file-size. So in my case I got 8Gb ram what is the best I should set for my log file size? What would the additional log file be named as if any? – newbie14 May 24 '12 at 13:15
  • That depends on the amount of InnoDB Data and Index Pages. innodb_log_file_size are supposed to be 25% of the innodb_buffer_pool_size. Please see http://dba.stackexchange.com/a/2194/877 for how to compute the proper size for your innodb_buffer_pool_size for your system – RolandoMySQLDBA May 24 '12 at 14:15
  • as I am just starting a new server so what is recommended setting for my case then since I dont have any huge data yet? Should I leave it and adjust later? – newbie14 May 24 '12 at 17:38
  • Since you do not have sizeble data yet, you can leave InnoDB in its default state for now. When that time comes, please refer to my post on setting up caching for your storage engines : http://dba.stackexchange.com/a/2194/877 – RolandoMySQLDBA May 25 '12 at 23:51
  • I dont see anything about caching for innodb just the innodb_buffer_pool_size is that what you meant by caching here? So the recommended size now is 563M. So my innodb_log_size should be then 140M. But on a daily basis my data will be growing so how to maintain the both this values innodb_buffer_pool and innodb_log_file. So anytime in between I can stop the mysql server remove the log file and re-size it wont have any impact is it? – newbie14 May 26 '12 at 02:49
  • You will have to plan this number based on RAM. Since you got 8GB of RAM, you should go with 6G for innno_buffer_pool_size and 1536M for innodb_log_file_size. – RolandoMySQLDBA May 26 '12 at 09:08
  • k I will go with your suggestion. But I am still unclear about why we should have big innodb_log_file. I read some said it will take a long time during recovery so what is your advice on that? – newbie14 May 26 '12 at 16:47
  • If you are using MySQL 5.1 or earlier, set innodb_max_dirty_pages_pct = 0; that will make shutdowns and startups of mysql faster. MySQL 5.5 flushes better and does not need such an adjust. – RolandoMySQLDBA May 26 '12 at 16:56
  • ok I will set that but now how about innodb_log_file one will keep the redo rite. Why do some articles says keep it low to avoid a huge time during recovery what is your opinion on that ? – newbie14 May 27 '12 at 12:26