In order to optimise my MySQL 5.1 (running on Window 2008 WebServer). I changed a few InnoDB options in my.ini namely the innodb_buffer_pool_size and innodb_log_file_size. But now when I am trying to restart the service it won't start. In the event viewer I can see the following errors:

Unknown/unsupported table type: INNODB

I have read about deleting log files and then starting the service but I have no clue where those log files are on windows machine. Also what is the best way to recover from this trauma without loosing any table data ?

  • Please run the following queries: show variables like 'innodb_buffer_pool_size';, show variables like 'innodb_log%';, show variables like 'innodb_data%';. Please also show what these variable settings look like in my.ini Feb 2, 2012 at 21:36

2 Answers 2


Yup, you'll need to remove the log files to change their sizes. They're in where ever your DATADIR is. Just make sure you remove them when the server is shutdown. Then restart and you'll be fine (it will recreate them).

DO NOT remove any ibdata files, though. That has your actual persistent data.

  • still won't start
    – Shahid
    Feb 2, 2012 at 19:50
  • by the way I found the log files under c:\documents and settings\all users\application data\mysql\mysql server 5.1\data
    – Shahid
    Feb 2, 2012 at 19:51
  • I don't suppose you have skip-innodb in your my.ini?
    – atxdba
    Feb 2, 2012 at 20:40
  • No .. got it working now thanks ... I was trying to run the 'reconfigure mysql instance' tool to get it working but that never worked and displayed a red cross next to 'Start Service' on the last screen. But when I checked the MySQL service under the Services, it was running and I could stop and start it ...
    – Shahid
    Feb 3, 2012 at 8:47

What does this return?

show engines;
SHOW VARIABLES LIKE 'have_innodb';

Innodb should be included in output.

  • show engines shows InnoDB as DEFAULT and MyISAM being supported as well
    – Shahid
    Feb 3, 2012 at 10:52

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