Hardware Reference
In-Depth Information
aligned partitions to first partition the drive, and then install the older OS into the already
existing aligned partition.
Note
For more information about using large sector drives with Windows (including updates
needed for some versions of Windows), see the Microsoft Knowledge Base article number
2510009, “Information about Microsoft support policy for large sector drives in Windows,”
You can use at least two methods to check the alignment of a partition under Windows.
One is to open a command prompt and enter the following command:
wmic partition get Name, StartingOffset
Thecommandresultshowsthestartingoffsetofallthepartitionsonallthedrivesconnec-
ted to the system. For example, here is the output after running the command on a system
with two drives installed, each with a single primary partition:
Name StartingOffset
Disk #0, Partition #0 32256
Disk #1, Partition #0 1048576
Another method istorunthe msinfo32.exe program at acommand prompt orvia the Start
menuunderPrograms,Accessories,SystemTools,SystemInformation.Oncetheprogram
is running, in the left pane select Components, Storage, Disks. Then in the right pane find
the Partition and Partition Starting Offset figures for each of the drives/partitions in the
system.
Inthisexample,thefirstdrivehasastartingoffsetof32,256bytes.Toseeifthiswouldbe
aligned on a 4K sector drive (or SSD), divide that number by 4,096. The result is 7.875,
which is not an even number, indicating that this partition is
not
aligned. This is in fact
the standard offset created by a non-4K aware OS such as Windows XP, and it is equal to
63×512 bytes, indicating that the partition starts at LBA 63.
To check the alignment for the partition on the second drive, divide the starting offset of
1,048,576 by 4,096. The result is an even 256, which is an even number, indicating that
this partition is properly aligned. This in fact is equal to 2,048×512 bytes, indicating that
the partition starts at LBA 2,048.
If you have misaligned partitions, you can use a third-party partitioning program like Par-
tedMagic(
www.partedmagic.com
)tobothcreatealignedpartitionsaswellasmoveexist-
ing partitions into alignment. In addition, most if not all the drive manufacturers that sell
4K sector drives (including SSDs) offer partition alignment utilities that can take existing
partitions and align them. Check with your drive manufacturer to see if such a utility is
