After some attempts I managed to figure out how to do it by Graphic Interface, using only 2 bash commands to mount the copied disk.
Here I report the steps to achieve this task (sorry if the screenshots are in Italian, I can't change the language of Azure interface):
go on the top of the menu, in the search-bar and type "snapshot", for then clicking on the Snapshot service
click on add button
in the new menu select the source disk that you want to copy ("Disco di origine" in Italian)
when created the snapshot of the disk that we want to copy, go in the search-bar of the 1st point and this time search for "disks", for then clicking on Disks service
click on add button just like in the 2nd point
here in Source snapshot ("Snapshot di origine" in Italian), you can specify the snapshot that has been just created
At this point we have a copy of the disk, now we want to use it as a disk for another VM. So:
- go on the desired VM to which we want to attach the disk and search for "Disks" and click there
- click on "Add data disk" on the bottom of the new menu
- select the disk that has been just created
- connect in SSH to the VM (I assume you are using Ubuntu server and so bash command line) and type
sudo mount -t ext4 /dev/sdc /path/of/mounting/point
type sudo nano /etc/fstab
and edit the file adding the following line
/dev/sdc /datadrive ext4 defaults,nofail 1 2
(I have not enough reputation to post picture here, please help me to reach only 10 and I can post here the screenshots)