Cannot Upgrade Basic Disk Containing a Single EISA Partition to Dynamic Disk

When you use the Windows 2000 Disk Management snap-in to upgrade a basic disk that contains a single Extended Industry Standard Architecture (EISA) partition to dynamic disk, the conversion appears to work but the EISA partition disappears and the entire disk is then displayed as unallocated free space. If you quit and then restart Disk Management, the affected disk status changes to "Dynamic Unreadable." If you shut down and restart Windows 2000, Disk Management shows the disk is once again a basic disk and the EISA partition is still intact.

This entire process repeats if you make subsequent attempts to convert the disk to dynamic disk.

To work around this problem, use the following steps:

1. Temporarily create another primary partition of any size on the disk that contains the EISA partition.
2. Convert the disk to dynamic disk.
3. Quit and restart Disk Management.

The disk is now a dynamic disk and the EISA partition is intact. You can now safely delete the temporary partition.

NOTE: The EISA partition is always displayed as the second partition in the Disk Management graphical user interface (GUI). For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

You may want to use Windows 2000 mirroring to mirror the system/boot drive. You may also want to have the shadow drive contain an identically sized EISA partition on the shadow drive so that after mirroring, both the primary and shadows drives are identical. Some Original Equipment Manufacturer (OEM) drives may include an EISA partition already on the drive. Before mirroring is allowed, you must convert the drive to dynamic disk, which may lead to the problem described in this article