Extending Hardware RAID Array May Cause Dynamic Unreadable/Offline Error (294244)


The information in this article applies to:

  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Advanced Server SP1
  • Microsoft Windows 2000 Advanced Server SP2
  • Microsoft Windows 2000 Professional SP1
  • Microsoft Windows 2000 Professional SP2
This article was previously published under Q294244

SYMPTOMS

Windows 2000 supports dynamic disks which may be contained on a hardware raid array. Some hardware RAID arrays allow you to add more drive space to extend the RAID array. This adds the new free disk space to the end of the existing disk. Normally when this is done, the new drive size is displayed in the Disk Management tool, and the extra free space appears at the end of the existing drive. This allows you to create new volumes or extend existing volumes to include the new free space that was added to the array.

After you extend a hardware RAID array for the second time and then restart Windows 2000 or the Disk Management tool, you may lose access to any volumes that are contained on that drive. Windows 2000 Disk Management could display dynamic disks with missing volumes that were created since the first extension or will show the newly extended drive or drives as one of the following.

Dynamic Unreadable

If you only have a single dynamic disk, after a reboot or a restart of Disk Management, the extended dynamic disk appears as "Dynamic Unreadable".

Dynamic Online

If you only have a single dynamic disk, after a reboot or a restart of Disk Management, the extended dynamic disk appears as "Dynamic Online". However, all the volumes that are contained on the dynamic disk have disappeared, and the only available recovery option is to choose the Revert to Basic Disk option.

Dynamic Offline

If you only have a single Dynamic disk, after a reboot or a restart of Disk Management, the extended dynamic disk appears as "Dynamic Offline". If you try to re-activate the disk, you receive the following error message:
Internal Error - Disk Group has no valid configuration copies.
If you have more than one dynamic disk in the computer, after a reboot or a restart of Disk Management, the extended dynamic disk appears as "Dynamic Offline". If you try to re-activate the disk, you receive the following error message:
Internal Error - Disk Public Region is too small.

CAUSE

Dynamic disks contain a database at the end of the physical disk, Logical Disk Manager (LDM) keeps track of where the current database is located when a drive is first converted to dynamic by recording a pointer to the database in a backup LDM header. When you extend a hardware RAID array, Disk Management reads the backup LDM header, and then moves the LDM database to the new end of the physical disk. When you grow the disk the first time, the relocation succeeds because the stored LDM backup header points to the present location of the LDM database. However, the stored backup header information is not updated to point to the newly relocated database after the relocation succeeds. The next time you grow the disk, the same LDM backup header is read, but this time it is incorrect and instead points to the location of the old LDM database that was previously moved. This causes the relocation of the present database to not work because an erroneous attempt to try to move the old obsolete database is made (which may have already been partially or completely overwritten with user data) to the end of the new physical drive.

RESOLUTION

If the computer contains more than one dynamic disk, and you are encountering the last error message that is listed in the "Symptoms" section of this article, a system reboot should resolve the problem.

For any of the other error messages, you must contact Microsoft Product Support Services (PSS) to locate the old database and correct the pointer in the backup LDM header. This allows the correct database to be relocated the next time the system is rebooted. For information about how to contact PSS, please view the following Microsoft Web site:

http://support.microsoft.com/directory/question.asp

To prevent these symptoms after future expansions apply the following fix.

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later: 
   Date        Time     Version           Size      File name
   ----------------------------------------------------------
   5/14/2001   04:41p   2195.3609.297.3   369,008   Dmboot.sys
   5/14/2001   04:47p   2195.3609.297.3   316,176   Dmconfig.dll

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.

MORE INFORMATION

It is possible to prevent this problem from occurring if your hardware RAID array allows you to extend it "online" while Windows 2000 is running and you follow these steps:
  1. Extend the hardware RAID array online, and have Windows 2000 Disk Management open at the time of the hardware array extension.
  2. After the hardware array is extended, click Rescan Disks on the Action menu. This allows Disk Management to read the header that is cached in memory since Disk Management was first started and move the LDM database to the new end of the physical disk.
Modification Type:MinorLast Reviewed:9/26/2005
Keywords:kbHotfixServer kbQFE kbbug kbenv kberrmsg kbfix kbHardware kbOSWin2000fix kbWin2000sp3fix KB294244
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