Dynamic disk offline case study
"Dynamic Disk offline on Windows 2000
I have one Server IBM System X3650 configure with Windows 2000 Server Sp4. 4 HDDs
attached with that Server and have two Array of RAID 1. Disk 0 configure as Basic
disk and Disk 1 configure as Dynamic disk. Each time the Server reboot Disk 1 will
become offline. Is there any idea to solve. I have already edited the registry and
change the dmboot start value to 0. But the problem still persists each time the
What cause offline dynamic disk?
When a dynamic disk is inaccessible, an error icon "Offline" appears on the dynamic
disk. The message indicates dynamic disk may be corrupted or intermittently
unavailable. Sometimes the disk name will change to "Missing" while the "Offline"
status occurs. Such alteration states the dynamic disk was recently available on the
system but can not be located or identified any more. The missing disk may be
corrupted, powered down, or disconnected. The two causes below is common reasons why
dynamic disk offline.
Cause1: Controller driver is not started at boot
In the event that the driver for the second mass storage controller is not set to
start at boot, the devices under the controller may be unavailable to use after
system has started. In the built-in Disk Management, the dynamic disks may shows up
Cause2: Extend Hardware RAID Array
As is known to us all dynamic disks contain a database at the end of the physical
disk. The Logical Disk Manager, or LDM for short, keeps track of where the current
database is located. And a backup LDM header will record a pointer to the database
when the disk is first converted to dynamic. Extending a hardware RAID array may
cause the relocation of the present database to not work because an erroneous
attempt 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
How to bring a dynamic disk that is offline and missing back online
Repair any disk, controller, or cable problems and make sure that the physical disk
is turned on, plugged in, and attached to the computer.
Solution1: To reactivate a dynamic disk with Disk Management
In snap-in Disk Management, right click the dynamic disk displays missing or offline
and select "Reactivate Disk". The dynamic disk should be shown as "Online" after
Solution2: To reactivate a dynamic disk by using Diskpart Command Line
Step1: Open a command prompt and type "diskpart". In the command-line
interface, type "list disk" to display all disks.
Note: Missing disks are numbered M0, M1, M2, and so on, and offline disks are
numbered 0, 1, 2, and so on.
Step2: Type "select disk number".
Step3: Type "online".
Tips: For Windows 2000, you need to download the diskpart command prompt utility.