To add external hard disk
Login to HyperV Manager.
Power down the the VM where you have to add an external disk.
Right click on the VM. Click Settings.
Select SCSI Controller, select Hard Drive and click Add.
Ensure Location is set as 2 and select Virtual hard disk and click New to create a new data disk.
In New Virtual Hard Disk Wizard, click Next.
Navigate to Choose Disk Format, select the option that suits your host storage needs.
Click Next.
In Specify Name and Location, enter and name and browde the location for the hard disk.
Click Next.
In Configure Disk, select Create a new blank virtual hard disk and enter the Size of the virtual hard disk as per your requirement.
Click Next.
Click Finish.
Click Apply.
Click OK.
To connect to the console, select the NSM On-Premises instance with a left-click and then right-click to select Connect.
In the CLI console type show disks.
Initialize the disk.
Type disk initialize.
Enter the name of the disk to initialize.
Type yes when prompted for confirmation.
Enter a new password when prompted for password.
Activate the disk. Type disk activate. It will reboot the VM and mount the disk on boot. Please enter the password when prompted.
The password is the password that you have configured in step 18 above.
After the VM reboots, the disk will be active.