Win98 300x225When is high availibility not? 

When its any version of SQL running on a clustered Windows 2003 Server or sql 2005 running on clustered Windows 2008 Server.  Seems that while you can dynamically add a disk and use it in SQL when your running a standalone server, if your running in a “highly availiable” cluster configuration you have to take SQL offline to add the disk as a dependency in order to be able to use it within SQL.  Here’s the proof right from SQL books online.

Im sure there was a good reason to require this at the time but clearly this wasnt thought out in the grand scheme of taking 0 downtime.  Anytime a single server has a more highly availiable architecture than your system that is designed for high availibility –>youre doing it wrong, Sorry someone had to say it