title: Free up space in MySQL 5.6.20 - InnoDB
body: <p>first off, not a DB guy. here is the problem, data drive for the database is 96% full. in the my.cnf there is a line that has the following, (only showing part due to space)</p>
  <pre><code>innodb_data_file_path=nmsdata1:4000M;nmsdata2:4000M; 
  </code></pre>
  <p>going up to</p>
  <pre><code>nmsdata18:4000M:autoextend
  </code></pre>
  <p>so in the folder where the files are stored files 1-17 are 4gb in size, file 18 is 136gb as of today.</p>
  <p>I inherited the system and it has no vendor support or much documentation.
  I can see there are a few tables that are really large</p>
  <pre><code>Table_name                             NumRows              Data Length
  ----------                             -------              -----------
  pmdata                                 100964536            14199980032
  fault                                  310864227            63437946880
  event                                  385910821            107896160256
  </code></pre>
  <p>I know ther is a ton of writes happening and there should be a cron job that tells it to only keep the last 3 months data but I am concerned the DB is fragmented and not releasing space back for use.</p>
  <p>so my task is to free up space in the DB so the drive does not fill up.</p>