Default password is changeme
The docs Set Up Azure Storage and Uploading the VHD · VMware Photon OS 3.0 Documentation uses the Linux Azure CLI command az vm create as there is an option --admin-username. The Azure powershell cmdlet New-AzVM does not offer something similar to --admin-username. I will change the script and post the result again.
It must have something to do with that post provisioning on Azure as pwd is not an issue on vSphere. For a password change using grub, the vm serial console in Azure resumes too late to enter grub boot menu during/after start up.
root didn't work because the Windows Azure Linux Agent makes password authentication for root account unavailable, right? photon/photondistroadd.patch at master · vmware/photon · GitHub
The PhotonOS 3.0 .vhd on Azure is provisioned with disabled root account by default. Therefore I wasn't able to login using the initial root pwd.
The powershell cmdlets new-azvm or az vm create do not accept pass the root user as --admin-username root or as -cred param. Another reserved username is 'admin' as well. Root must be re-enabled and set with a password.
sudo passwd -u root
sudo passwd root
(set new password)
su -l root
The semi-automated ps script works now :-) Using the az vm create --custom-data option, it may be possible to automate the post-provisioning part as well.