[This post was moved from my previous blog]
This is interesting if you are setting up a new SQL server.
If you are delivered a server ready for install SQL and dont know which allocation unit size the data disks are formatted with, then this is a nice way of telling if you should reformat or not.
http://ruiabel.wordpress.com/2012/11/14/how-to-check-allocation-unit-size/
Disks should be formatted to 64K for best performance for SQL 2008/2012.