HP StorageWorks SAN Virtualization Services Platform Administrator Guide (5697-0934, May 2011)

Download diskpart.exe from the Windows 2000 kit and place the executable
file in the Windows system path
a.
b. Click on Disk Management, and in the lower right hand side pane, note the disk
number of drive to be partitioned.
c. Open a command prompt and type diskpart –s for disk number.
d. Answer y to both questions for yes.
e. Enter 128 for starting offset (128 = 64K).
f. Insert desired partition size in MB.
g. Assign drive letter to partition and format it using Disk Management.
• Align partition with diskpart for Windows 2003 SP1 & R2:
a. Diskpart.exe is available on Windows 2003, however only the diskpart in
Windows 2003 SP1 and higher can align disks.
b. Open command prompt and type diskpart.exe.
c. Press Enter and type list disk.
d. Note disk number on which you want to create partition.
e. Press Enter and type select disk 1 (or other disk number).
f. Press Enter and type create partition primary align =64.
g. At the new prompt, type assign letter z (or other letter drive) or type assign
mount C:\Folder1 (or other path of empty directory to mount the drive).
h. Press Enter and type exit to leave Diskpart.
i. Format new drive using Disk Manager.
3. This section describes how to configure Windows Server 2003 disk partitions to be aligned
optimally for HP storage. The Windows Server 2003 default partition set does not align the
partition to the physical disk on which the partition resides. Correct partition alignment helps
reduce latency when the partition is written to, because it eliminates the unnecessary disk
writes and reads that occur when partitions are not aligned. Windows partitions should be
aligned at 64K for best results.
4. With a physical disk that maintains 64 sectors per track, Microsoft Windows always creates
the partition starting at the 64th sector—which misaligns it with the underlying physical disk.
To be certain of disk alignment, use Diskpart.exe, a disk partition tool. Provided by
Microsoft in the Windows Server 2003 Service Pack 1 support tools, Diskpart.exe can
explicitly set the starting offset in the master boot record (MBR). Setting the starting offset
correctly will align Microsoft Exchange I/O with storage track boundaries and improve disk
performance. Microsoft Exchange Server 2007 writes data in multiples of 8 KB I/O operations,
and I/O operation to a database can be from 8 KB to 1 MB. Therefore, make sure that the
starting offset is a multiple of 8 KB. Failure to do so may cause a single I/O operation to span
two tracks, causing performance degradation.
NOTE: This can only be done when creating a new partition before formatting. It is not
possible to align a partition that has data on it already without losing that data.
5. Align a partition with diskpart for Windows Server 2003.
a. Open a command prompt, type diskpart.exe, and press Enter.
b. Type list disk. Note the disk number on which you want to create a partition.
c. Type select disk (disk number).
d. Type create partition primary align=64.
e. Type assign letter (the drive letter). Or type assign mount (the path
of a empty directory to mount the drive).
f. Type exit to exit diskpart.
24 Adding devices to the domain