System or Boot Disk Listed as Dynamic Unreadable in Disk Management

ID: Q236086

The information in this article applies to:

Microsoft Windows 2000 Advanced Server
Microsoft Windows 2000 Datacenter Server
Microsoft Windows 2000 Professional
Microsoft Windows 2000 Server

SYMPTOMS

When you view your system disk or boot disk in the Disk Management tool, it may be listed as "dynamic unreadable", and you may be unable to use the Disk Management tool to manage this disk. Note that this behavior may occur even though the operating system is currently running from your system disk or boot disk. Your original dynamic system disk or boot disk may now be listed as "Missing" - "Offline", and all volumes contained on the missing disk are noted as "failed" and are not accessible. If you then try to reactivate the missing disk, you may receive the following error message:

The specified disk could not be located.

Also, the System Event log may contain entries for each "failed" volume contained on the missing dynamic disk:

Event ID: 3
Event Source: dmboot
Description: dmboot: Failed to start volume Sysdrive (C:)

CAUSE

This problem can occur if Windows 2000 was re-installed and during Setup a volume on the dynamic disk was deleted and recreated, or another disk partitioning tool like Fdisk was used to create a new partition. Windows 2000 Setup and other disk partitioning tools can only create basic partitions. Creating any partitions on a dynamic disk outside of Windows 2000 or during Setup creates a disk with both dynamic and basic partition table entries. Re-creating a volume during Windows 2000 Setup changes the partition system-id byte from type 0x42 (dynamic) to a basic partition system-id byte based on the file system chosen, usually 0x06 for FAT, 0x0B for FAT32 or 0x07 for NTFS. Anytime there is a mix of basic and dynamic system-ID bytes, the disk will be viewed as Dynamic Unreadable in Disk Management.

RESOLUTION

WARNING: Do not delete any of the missing or offline dynamic disk volumes, especially if they were part of a spanned, striped, or a Raid-5 volume. Doing so could lead to permanent data loss.

To work around this problem, use a disk editor (such as DiskProbe) and change the offending system or boot partition system-ID back to a type 0x42. Please note that doing so may make your compute unbootable if the associated LDM database containing the original partitioning scheme does not agree with the partitioning scheme created when Windows 2000 was reinstalled. After manual repairs are made, and your computer starts successfully, the dynamic disk should be recognized and associated volumes should become accessible again.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

Q227364 Dynamic Volumes Are Not Displayed Accurately in Text-Mode Setup

Information about Dskprobe, partition tables and system-IDs are detailed in the Windows 2000 Resource Kit. Dskprobe can also be found on the Windows 2000 CD-ROM in the Support\Tools folder.

Additional query words: ldm veritas fdisk win2000hotsetup

Keywords : kbtool kbui
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbprb