Case study: dynamic disk missing failed or offline
Case 1: I recently installed a 3TB SanDisk disk last week to my
Windows 7. After finishing the installation, the hard drive
showing wrong capacity, so I converted it to GPT and was able to see the
full size. However, it is divided into two partitions, one with 2TB and one with
0.7TB. Since I want to merge them into one partition, I changed the disk into a
dynamic disk from basic. Everything goes fine until last night a sudden power
failure occurs while I was using my computer. When the computer booted again, the
CHKDSK launched automatically, but when I got to windows, my hard drive was not
visible. In disk management, the 0.7tb disk volume appeared as missing.
Case 2: I removed a dynamic disk from my old PC, and connected it up
to my new PC as the 2nd disk. The new PC started up and the new hardware icon
appeared briefly in the systray. It was working flawlessly before the switch. But now the dynamic disk shows offline in device manager. Any ideas of what I can do to deal with this issue?
Why dynamic disk shows missing or offline?
After scanning over the dynamic disk missing issue, you might be curious about why it happens.
Generally speaking, a dynamic disk may display Missing status when it is corrupted, powered down or disconnected well. For an offline dynamic disk, it may because you attempt to import a foreign dynamic disk but fails. In either case, you will not be able to see, not to mention access the dynamic disk in File Explorer.
How to fix the missing dynamic disk easily in Windows PC?
Here comes the crucial part: how to fix dynamic disk missing or offline issue in Windows PC?
In order to get your dynamic disk to Online or healthy status, you can reactive it in Disk Management or Command Prompt.
Note: Only dynamic disks can be reactivated and online.
To reactivate a dynamic disk using Windows Disk Management
Step 1. Right click “This PC/My computer”->”Manage”->”Storage”->”Disk Management” to enter into device manager. And right click the missing/offline dynamic disk and click “Online”.
Step 2. If the disk appears in Disk Management as Online, and has a primary partition shown as Healthy like the picture below, that means the disk has been take an online/healthy status.
To reactivate missing or offline dynamic disk via Command Prompt
Step 1. Press the “Win + R” keys on your keyboard. Then, type “cmd” and right click the Command Prompt icon to select “Run as administrator” to open the Command Prompt Window.
Step 2. In the Command Prompt window, type “diskpart” and press “Enter”. Then execute the following commands.
Note: check the disk number of the missing or offline dynamic disk you want to bring online. Missing disks are numbered M0, M1, M2 and so on while offline disks are numbered 0,1,2.
select disk <disknumber>.
Tip: if your dynamic disk has I/O errors on a region of the disk, you will see “Error” word on the dynamic disk. If the I/O errors are temporary, you can reactivate the disk to return it to Online status.
Finally, you should run Chkdsk.exe to make sure that the underlying file system structure is in a good condition.
For this task, you just need to execute the command: “chkdsk x: /f” (where x is the drive letter of the volume you want to check and /f option is used to tell CHKDSK to fix any errors it detects) in the Command Prompt window.
Till now, you will be able to get rid of dynamic disk missing problem. To solve dynamic disk missing issue in Windows Server 2008, 2012, 2016 or 2019, you can also run the same commands to reactive it.
Further reading：How to better manage the Dynamic Disk?
If you want to manage your dynamic disk and volumes more easily, you can use a professional dynamic disk manager like AOMEI Partition Assistant Professional.
It comes with tool named AOMEI Dynamic Disk Manager, allowing you to shrink volumes, delete volumes, add drive to RAID, removing drive from RAID. etc. Apart from the basic features, this dynamic disk manager also has the following advanced functions:
“Resize Volume” could help you to free up some unallocated space, or extend/enlarge one certain volume to fix low disk space problem, especially for the system volume.
“Format Volume” allows you to change File System or Cluster Size, or Volume Label easily, quickly and safely.
“Move Volume Slice Wizard” makes it possible to transfer volume slice from one disk to another, which is quite useful when you want to extend the system volume but no contiguous unallocated space available, or other volumes without free space to be shrunk.
Most importantly, when you want to convert disk from dynamic to basic but don’t want to delete all volumes/lose data on the disk (which is a necessary process if you perform the conversion in Disk Management), AOMEI Dynamic Disk Manager is able to convert dynamic disk to basic without losing data.
To sum up
So, this article not only tells you how to deal with dynamic disk missing or offline issue but also shares a great dynamic disk manager tool to better and easily manage the dynamic disk or volumes. To use this perfect dynamic disk manager in Windows Server, you can try AOMEI Partition Assistant Server.