The VM name must be 15 characters or less.
As entered on the Azure VM create page.
Remember, the word ‘snapcloud’ uses up 9 characters. This leaves 6 more chacters.
If you enter a name that is longer than 15 characters Azure will report the VM as failed.
Azure will allow the VM to continue booting, leaving the VM in a running state, but it will be reported as failed.
The ‘admin’ user is not created and the system is left in a half configured state.
If you have created a VM with more than 15 characters, you will need to clean up (stop the VM and delete the associated Resource Group) VMs that have names longer than 15 characters.