your storage vendor.
Use separate physical disks and LUNs for VM Guest operating system VHD files and data volumes.
Segregate disk I/O as per the Guest application‘s disk tuning guidance.
Utilize NTFS for all host server volumes.
In operating systems prior to Windows Server 2008, align the Guest disk sectors as per http://support.microsoft.com/kb/929491
Periodically defragmenting, pre-compacting, and compacting the VHD files on the guest and defragmenting the volumes on the host will help ensure optimal disk I/O performance. If using only fixed-size VHDs, host-level defragmentation of the volumes hosting VHDs is not necessary because the disk sectors are pre- allocated in a contiguous fashion at the time of creation.
Defragmentation of the host can be performed by using the built-in Microsoft Windows® disk defragmentation utility. Detailed instructions for VHD defragmentation, pre-compaction, and compaction can be found in this article: http://vscommunity.com/blogs/virtualzone/archive/2007/01/17/three- steps-to-vhd-compaction-with-virtual-server-2005-r2-sp1.aspx
Virtual Hard Disks (VHD) Virtual hard disks encapsulate a guest‘s hard disk inside of a VHD file, which is
placed on storage that is accessible to the host server. Utilizing virtual hard disks provides benefits such as the ability to dynamically expand the disk, the ability to take snapshots of the disk, portability in terms of moving the disk to a different server, and so on. There are three forms of virtual hard disks.
Dynamically Expanding Disks Dynamically expanding virtual hard disks provide storage capacity as needed to
store data. The size of the .vhd file is small when the disk is created and grows as data is added to the disk. The size of the .vhd file does not shrink automatically when data is deleted from the virtual hard disk. However, you can compact the disk to decrease the file size after data is deleted by using the Edit Virtual Hard Disk Wizard.