mbrscan is available for esx4.x as part of the Virtual Storage Console. You can run fdisk on the vmdk or log into the VM and verify. For Linux, of the vmdk directly, use fdisk, go into extended mode "x" then "p" to view the partition table. if the first sector starts at 63 instead of 64, then it needs to be aligned. for windows, use msinfo32. Expand Components/Storage/Disks, and look at "Partition Starting Offset". If the offset is 32,256 instead of 32,768, then it needs to be aligned.. Windows 7, and server 2008 are already aligned..