Policy-Based Management gives DBAs the ability to define and set policies (standards) and evaluate those policies against the instances of SQL Server in their environment.
The video below highlights some of the best practices you should apply to help minimize common problems and optimize the performance of Dassault Systèmes ENOVIA v6 on SQL Server 2008. One of the items discussed in the video is monitoring and managing your data and log file usage. Being aware as to how full your data and log files are is not only useful for capacity planning but allows you to control when and how your data and log files grow. Constantly growing your files causes unneeded IO operations and your data and log files end up in bits and pieces all over your disk. If your data is spread out all over the disk there is an the additional performance hit in reading that data.
Below are two policies available to download that (when evaluated) will check that your data and log files have at least 10 percent available space. This free space percentage is configurable by going into the Check Condition for each individual policy.
Check that all data files have at least 10% free space
Check that all log files have at least 10% free space
NOTE: SQL Server does give you the option to automatically grow your database and log files and I recommend that you leave this on as a "safety net" but ideally your database files will never grow through this automated process.
For information on Importing a Policy-Based Management Policy please see:
How to: Export and Import a Policy-Based Management Policy
For more information on Policy-Based Management please review the links below.
SQL Server 2008 Policy-Based Management white paper
SQL Server Policy-Based Management Blog
Enterprise Policy Management Framework