Unable to initialize virtual disk

Virtualization continues to mature and has become an extremely viable solution for both businesses and individuals to have their own virtual server.  Costs of servers have dramatically decreased as the back-end hardware costs are shared across a number of users.

With that being said, there are some obscure issues that arise on virtual servers.  One of those such issues is when you attempt to add a second virtual hard drive to a Windows server.  On the server under disk management you will see that the new disk that you added is showing offline.  When you try to bring it online in Disk Management, you are presented with this error message:

The disk is offline because of policy set by an administrator

You will note that this error is frequently encountered in both VMWare and Hyper-V virtual servers.  Despite the wording of the error message, it is not difficult to fix.

  1. Open a command prompt as an Administrator
  2. Open the DiskPart utility by typing:
  3. You will be presented with this prompt:
  4. Enter the following to view the SAN policy:
    DISKPART> san
  5. You should see the following:
    SAN Policy  :  Offline Shared
  6. Change the SAN policy to online by typing:
    DISKPART> san policy=OnlineAll
  7. You should see the following results:
    DiskPart successfully changed the SAN policy for the current operating system.
  8. Run the following to list the information about each disk:
    DISKPART> list disk
  9. Your results should look something like this:
    Disk ###   Status        Size        Free       Dyn    Gpt
    ———-    ————  ———  ———  ——  —-
    Disk 0        Online        50 GB     0 B
    *Disk 1      Offline        100 GB   1024 KB
  10. Select the offline disk by typing (replace the 1 from my example with your disk number):
    DISKPART> select disk 1
  11. You should see:
    Disk 1 is now the selected disk
  12. By default, the disk should be read-only so we want to remove that attribute with this command:
    DISKPART> attributes disk clear readonly
  13. You should see:
    disk attributes cleared successfully
  14. Let’s confirm that they have by listing the attributes:
    DISKPART> attributes disk
  15. Your results should look something like this:
    Current Read-only State : No
    Boot Disk : No
    Pagefile Disk : No
    Hibernation File Disk : No
    Crashdump Disk : No
    Clustered Disk : No
  16. Bring this disk online with the following command (replacing the 1 from my example with your disk number):
    DISKPART> online disk
  17. You should see:
    DiskPart successfully onlined the selected disk.

You should be all set from this point and able to mount the drive and assign it a drive letter.