In this article I’m walking you through how to setup data file free space monitoring using SQL Server 2008 Policy-Based Management feature. You may think “Hey dude this is not a monitoring tool…!” but my answer would be “We can make this feature monitor data files free space on a database or instance”
To which I would add, "and besides, what we're doing here is testing a databases adherence to a policy we have. What better place to do that, than a policy management tool?"
Good article. I only have one question: is there a reason you did Multiply(@Size,Divide(10,100)) rather than just Divide(@Size,10) ?