Managing a mirrored volume

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Source
Create and test a mirrored system or boot volume
To create a mirrored boot volume
Add a mirror to an existing simple volume
Break a mirrored volume into two volumes
Remove a mirror from a mirrored volume
Reconnect the disk and repair the mirrored volume
Reactivate a mirrored volume
Replace a failed mirror with a new mirror on another disk

slower RAID  Problem removing mirror from missing disk
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To create a mirrored volume

• Using the Windows interface
  
• Using a command line 

Using a command line

1. Open Command Prompt.
   
2. Type:
   diskpart
   
3. At the DISKPART prompt, type:
   list disk
    Make note of the disk numbers for the dynamic disks that will make up the mirrored volume.
   
4. At the DISKPART prompt, type:
   select disk n
   
5. At the DISKPART prompt, type:
   create volume simple [size=n] [disk=n]
   
6. At the DISKPART prompt, type:
   add disk n

Value	Description
list disk	Displays a list of disks and information about them, such as their size, amount of available free space, whether the disk is a basic or dynamic disk, and whether the disk uses the master boot record (MBR) or GUID partition table (GPT) partition style. The disk marked with an asterisk (*) has focus.
select disk	Selects the specified disk, where n is the disk number, and gives it focus.
create volume simple	Creates a simple volume. After you create the volume, the focus automatically shifts to the new volume.
size= n	The size of the volume in megabytes (MB). If no size is given, the new volume takes up the remaining free space on the disk.
disk= n	The dynamic disk on which to create the volume. If no disk is given, the current disk is used.
add disk= n	Mirrors the simple volume with focus to the specified disk, where n is the disk number. The specified disk must have unallocated space at least as large as the size of the simple volume you want to mirror.

Notes

• To perform this procedure on a local computer, you must be a member of the Backup Operators group, Administrators group, or you must have been delegated the appropriate authority. If the computer is joined to a domain, members of the Domain Admins group might be able to perform this procedure. As a security best practice, consider using Run as to perform this procedure. For more information, see Default local groups, Default groups, and Using Run as.
  
• To open a command prompt, click Start, point to All programs, point to Accessories, and then click Command prompt.
  
• You can create mirrored volumes only on computers running Windows 2000 Server, Windows 2000 Advanced Server, Windows 2000 Datacenter Server, or Windows Server 2003 operating systems.
  
• You need at least two dynamic disks to create a mirrored volume.
  
• Mirrored volumes are fault tolerant and use RAID-1, which provides redundancy by creating two identical copies of a volume.
  
• Mirrored volumes cannot be extended.
  
• Both copies (mirrors) of the mirrored volume share the same drive letter.
  
• You can create mirrored, striped, spanned and RAID-5 volumes using a combination of MBR and GPT disks, but the MBR cylinder alignment-restriction may cause some difficulties in creating mirrored volumes. Always mirror the MBR disk to the GPT disk to avoid cylinder-alignment difficulties.
  
• For more information about DiskPart, see Related Topics.
  

Information about functional differences

• Your server might function differently based on the version and edition of the operating system that is installed, your account permissions, and your menu settings. For more information, see Viewing Help on the Web.
  

See Also

Concepts

Using mirrored volumes
Create a mounted drive
Format a dynamic volume
Assign, change, or remove a drive letter
Delete a dynamic volume
Working with MMC console files
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