Understand Persistent VM Disk (2)

Since all persistent PVM disks are eventually stored in blob storage, there must be a way to manage these disks and the .vhd files in the blob storage. The tools and portal to manage these are simple and straight forward, but understanding below key concepts would be very helpful for you to use those tools.

There are three stages of a .vhd file or a PVM disk:

1. raw .vhd file in blob storage (use any blob explore tool to manage this)
2. .vhd files recognized by PVM as disks (use Azure portal to create/delete disk)
3. PVM disk attached to a PVM instance (use Azure portal to attach/detach disk)

O/S disk vs. Data disk: this is decided when you recognize a raw blob file as a disk. O/S disk can be used to create a VM instance.

Image vs. Disk: Image is "sysprepared" O/S disk. You can use either Image or O/S Disk to create a VM instance. If you use O/S Disk, all the old user name, machine name etc. persist, while everything is as from scratch if you use Image.