i m using username,pwd ="root"when i try to deploy the vm, the vnc got opened but the login issue was coming stating “Login incorrect”. PFA for screenshot.
! vnc|690x387
assuming your using KVM, please see here some info about VM changes using contextualization:
http://docs.opennebula.org/5.4/operation/vm_setup/kvm.html
Apparently, you try to set username/password from a template, opennebula (normally) uses SSH keys to give access to the owner of a VM. (see: SSH_PUBLIC_KEY)
Besides that, I wouldnt user root/root as credentials, a VM like that will be a spam-server within 10 minutes 