Hyper-V and 4k “advanced sector” hard drives

As you may know, all newer hard drives are being shipped with 4k sector sizes.  If you would like more detail on this, please see http://www.bit-tech.net/hardware/storage/2010/04/01/the-facts-4k-advanced-format-hard-disks/1

I recently purchased one of the new Western Digital 3TB USB drives for use on one of my DPM servers, which is a Hyper-V guest.  Unfortunately, when I started to try to use the disk, Hyper-V refused to create new VHD files on the disk, or to boot VHD files that were manually copied to the disk.  All other functions seemed fine.

After trying a multitude of formatting and partitioning options and speaking with a couple of higher-ups at Western Digital, I realized there was a fundamental incompatibility between Hyper-V and 4k physical sectors.  I was planning to return the drive, but got caught up in some other projects and got back to this project yesterday to find a new KB article that seems to have been pulled – but thanks to google cache it’s still readable: http://support.microsoft.com/kb/2515143

It references not only the root problem but a hotfix (that is also included in the recently released Service Pack 1 for Win2008R2): http://support.microsoft.com/kb/982018

I decided to download and try the hotfix on a non-production Hyper-V server.  Here is what you get when using an advanced format disk on Windows 2008 R2 RTM Hyper-V:

And following the patch and reboot I now get…

…the exact same error.  Sad face.  Creating the VHD elsewhere and copying it over still doesn’t work either as Hyper-V still squawks about compatibility; looks like MS has more work to do:

UPDATE 4/18/2011: As you can see from my above edit, there is a new KB article specifically addressing this issue WRT hyper-v – and the bottom line is you cannot put VHDs on native 4k sector disks (and disks with 512b emulation will take a performance hit)…  bummer!