You can see my previous article to create your first Windows Server 2016 Core with Containers Tech Preview Virtual Machine in Azure,
Prerequisites
Now, let's start with the following steps:
Search the virtual machine
- Sign in to the Azure portal.
- On the Hub menu, click virtual machines.
- Select the virtual machine from the list.
- Under essentials, click all settings and then click disks.
Attach a new disk
- On the Disks blade, click Attach new.
- Review the default settings, update as necessary and click OK.
- Azure creates the disk and attaches it to the virtual machine, the new disk is listed in the virtual machine's disk settings under data disks.