mount a new data disk on an Azure Linux VM

https://blog.e-zest.com/how-to-create-attach-and-mount-a-disk-to-linux-vm-microsoft-azure

Basically create the disk from the Azure portal, then

• find the name of the device using dmesg - for eg. /dev/sdc
• sudo fdisk /dev/sdc
• sudo mkfs -t ext4 /dev/sdc1
• sudo mkdir DriveFolder; sudo mount /dev/sdc1 DriveFolder
• append to /etc/fstab using sudo blkid to find the UUID of the disk. Eg. 
  UUID=33333333-3b3b-3c3c-3d3d-3e3e3e3e3e3e   /datadrive   ext4   defaults,nofail   1   2
  

https://docs.microsoft.com/en-us/azure/virtual-machines/linux/attach-disk-portal
has a better set of instructions.