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Difference between Image , VHD and Snapshot in Azure


I was able to take a snapshot of OS Disk of VM1 and create a disk out of it. I have swapped with the VM1 OS Disk for learning purpose. I'm aware we can also create a new VM out of this snapshot as well.

There is another way to create a blob storage with VHD file and create a managed OS disk by selecting OS type as Windows/linux and then swap with VM1 OS Disk.

There is also a way to create an image by selecting same VHD file and create a completely new VM out of it.

I want to understand in detail the difference between Image, VHD and Snapshot.

  1. Is Image = VHD bundled with OS.
  2. Does VHD contain OS?
  3. Is Snapshot a VDH at a point of time?
  4. Does Snapshot contains OS as well?

Thank you very much in advance.


Solution

  • Well, if the existing issue does not answer solve the question. I would show you something that I understand about the three things via answer the four questions.

    Is Image = VHD bundled with OS.

    I think it's not. The image can contain the OS disk and the data disk. So you can treat it as a thing that contains multiple VHD files. And the OS disk is the must-have for the image.

    Does VHD contain OS?

    No, VHD is a format of a file that contains a virtual hard disk used by Microsoft Windows Virtual PC. The hard disk can be the OS disk or the data disk, but not both.

    Is Snapshot a VHD at a point of time?

    Yes, the snapshot is a full, read-only copy of a virtual hard drive (VHD).

    Does Snapshot contains OS as well?

    Perhaps. If the snapshot is a copy of the OS disk, of course, it contains the OS disk. But if the snapshot is a copy of the data disk, then it doesn't. You can tread snapshot the same as the VHD file in a special moment.