The recommended disk setup for hyper-v on Windows Server 2008

Here's a nice blog post: http://sqlserveradvisor.blogspot.com/2009/03/sql-server-disk-configuration.html

White paper on disk alignment: http://msdn.microsoft.com/en-us/library/dd758814.aspx

In short your OS should be on RAID 1, your data files on RAID 10 (preferably) and log files on RAID 1.

SQL Performance article: http://www.sql-server-performance.com/faq/raid_1_raid_5_p1.aspx

PDF on top 10 best performance tips: http://www.stlssug.org/docs/Best_Practices_for_Performance.pdf

Also remember to put your TEMPDB on a separate disk for performance reasons. I'm sure Paul Randal will come in here and blow your mind with why in a bit.

MS says why for tempdb: http://msdn.microsoft.com/en-us/library/ms175527.aspx

Ok - to make this clear...

If you are creating volumes on Windows Server 2008, you do not need to be concerned about the volume's partition offset because Windows Server 2008 will automatically set is to 1MB, which is a multiple of the common RAID stripe sizes and NTFS allocation unit sizes (both of which you should usually have set to 64K, unless you I/O subsystem won't let you go below 128K for the RAID stripe size - which is fine). In your question, you mention partition size, and what you're actually talking about is the NTFS allocation unit size (default 4K).

If you are installing a new Windows 2008 Server and then attaching volumes to it that were actually created using Windows Server 2003 or before, then unless you have previously used diskpart to change the partition offset from the default of 32.5K (63 x 512byte disk blocks), you must manually change it with diskpart, or recreate the volume.

My preference would be to backup your databases and then restore them on newly created volumes.

Hope this helps!

PS My blog post that you reference talks about having the correct partition offset, not partition size. And the whitepaper link in the first answer is the same one that I reference in the blog post you've already read.