Ask Microsoft: How can I increase the capacity of my system volume?

A Microsoft engineer offers advice on how to expand the system volume on a server running Windows Server 2003 by using the Diskpart utilty.

Question: I have a Hewlett-Packard Proliant ML-350 with a Compaq SmartArray 532 SCSI controller and four 18.2GB hard disk drives configured as one logical RAID 5 volume (three data disks and a hot spare) running Small Business Server 2000. I have updated the machine to SBS 2003 Premium Edition and added two 36.4GB hard disk drives to the array using the Compaq Array Configuration Program.

However, the operating system Disk Manager will not allow me to increase the capacity of my system volume. I can only use the new disk capacity to create a new volume. How can I solve this problem?

I know this is an operating system problem as the Compaq Array Configuration Program correctly integrates the new disks into the existing array. Unfortunately, Microsoft Partner Support says I can only extend a system volume by reformatting the drive and reinstalling the server or using a third-party solution, but they won't tell me which third-party solution they mean.

I previously used PowerQuest Volume Manager 2.0 with Windows NT 4.0 and Windows 2000 Server to manage array partitions, but this software has been bought by Symantec and they have informed me that it is not compatible with Windows Server 2003. I can't be the only person in the world with this problem. Any ideas?

Answer: There is no way to extend the system volume with the operating system booted.

You can however expand the system volume on a server that is booted from an NTFS boot disk using the Diskpart resource kit utility if there is contiguous space available of the disk as per the example below.

Note: Contiguous space may be achieved by moving existing partitions on the disk supporting the boot volume. Ensure that all data is backed up, inasmuch as this is not a supported approach.

With the system booted using an NTFS boot disk, the volume can be extended by running Diskpart.exe from a command line

There are a number of commands available associated with the Diskpart utility. Listed below are the ones that matter for this operation.

DETAIL -- Provide details about an object.
EXTEND -- Extend a volume.
SELECT -- Move the focus to an object.

Type the following commands in full or in short using the first three letters as highlighted below:

DriveLetter:> Diskpart.exe

DISKPART > Select Disk 0 ("This assumes that LUN 0 is your boot disk")
Disk 0 is now the selected disk.

DISKPART > Detail Disk
Controller Type SCSI Disk Device
Disk ID: 2FE43460
Type : SCSI
Bus : 3
Target : 0
LUN ID : 0

Volume ### Ltr Label Fs Type Size Status Info
---------- --- ----------- ----- ---------- ------- --------- --------
Volume 1 C NTFS Partition 68 GB Healthy System

DISKPART > Select Volume 1
Volume 1 is the selected volume.

DISKPART > Extend Size=10000 ("10000 will expand the disk by 10GB as an example, if no size is specified all available space will be allocated to the partition") Disk Part successfully extended the volume.


Boot the server into Windows and the system will have an extended boot partition.

-- Dave Lalor, Senior Engineer, Microsoft Exchange Center of Excellence

On a semi-regular basis, top Microsoft executives answer readers' technical questions about Windows-based systems. This installment of "Ask Microsoft" was answered by Dave Lalor, Senior Engineer, Microsoft Exchange Center of Excellence.

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