uniqueid


The disk is offline because it has a signature collision with another disk that is online 1

Recently, we cloned a hard disk using dd.
When we booted into Windows, the new drive was not visible.
After checking with the disk utilities, we got the following informative message:

The disk is offline because it has a signature collision with another disk that is online

To resolve the issue, we used diskpart.
To start diskpart, press the key combination Win + R which will pop up the Run prompt.
Type diskpart in the input box and hit the Enter key.

A new terminal window will appear.
Using that we identified the two disks and changed the label for the second one.

First step:

We issued list disk to get the list of disks.

DISKPART

Microsoft DiskPart version 10.0.14393.0
Copyright (C) 1999-2013 Microsoft Corporation.
On computer: BYTEFREAKS-NET

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          931 GB      0 B
  Disk 1    Offline         465 GB      0 B

Second step:

We issued select disk 1 so that we could process the disk 1 that was offline and using uniqueid disk we got the signature of the disk.

DISKPART> select disk 1
Disk 1 is now the selected disk.

DISKPART> uniqueid disk
Disk ID: 09FC13CB

Third step:

Set the signature of the disk to a random value other than the one that it already had using the command uniqueid disk ID=FFAABBCCDD

DISKPART> uniqueid disk ID=FFAABBCCDD

DISKPART> uniqueid disk
Disk ID: FFAABBCCDD

The random value must be 8 characters long and each character must be a value between 0-9 or A-F.

Finally:

Restart the machine to get both disks running.