Restrictions on Extending or Spanning Simple Volumes on Dynamic Disks (225551)

SUMMARY

Simple volumes on dynamic disks can be extended on the same disk or set to span other disks, without restarting the computer, when more disk space is required. You can extend a simple volume only if the file system is NTFS. A spanned volume, which is a simple volume that exists on more than one disk, can initially be created with the FAT or NTFS file system. However, after a simple or spanned volume has been created with the FAT file system, it cannot be extended or spanned further. You can reformat the volume using NTFS and regain the ability to extend or span the volume.

MORE INFORMATION

Note that if the volume existed before the disk was upgraded to dynamic, it can never be extended or spanned no matter which file system it uses. If you try to extend this type of volume, you receive the following error message:

The selected volume was originally created on a basic disk and cannot be extended. Only volumes originally created on dynamic disks can be extended.

To extend or span a volume that was created before the disk was upgraded to dynamic, the volume must be deleted and re-created on the dynamic disk.

A simple volume cannot be extended or spanned in this situation because any existing basic partitions retain their partition table entries in the master boot record (MBR) so that Windows 2000 can boot from and install to the dynamic volume. Setup allows only installations and upgrades to dynamic disks that currently include the system or boot volumes. Extending or spanning a simple volume that still has a partition entry would disable this ability.

Note Per Windows 2000 Help, you cannot extend a System or Boot volume.
For additional information about dynamic disks and Logical Disk Manager, see the following articles in the Microsoft Knowledge Base:

175761 Dynamic vs. Basic Storage in Windows 2000

222470 Dynamic Disk Numbering and the DmDiag.exe Tool

222189 Description of Disk Groups in Windows 2000 Disk Management