surabhi@surabhi-Inspiron-5520:~/openstack/devstack$ sudo /home/surabhi/openstack/devstack/tools/create-stack-user.sh
Giving stack user passwordless sudo privileges
surabhi@surabhi-Inspiron-5520:~/openstack/devstack$ su stack
Password:
su: Authentication failure
surabhi@surabhi-Inspiron-5520:~/openstack/devstack$ sudo -s
root@surabhi-Inspiron-5520:~/openstack/devstack# passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
root@surabhi-Inspiron-5520:~/openstack/devstack# su stack
stack@surabhi-Inspiron-5520:/home/surabhi/openstack/devstack$