The default root user of Ubuntu system cannot log in, and the password is also empty.
If you want to log in with the root user, you must first set a password for the root user
Open a terminal, type: sudo passwd root and press enter
At this point you will be prompted to enter a password, enter the password of the user you are currently logged in after password:
In the ubuntu system, the default is to disable ssh and use the root user to log in. The following configuration is made in the /etc/ssh/sshd_config configuration file:
# Authentication:
#PermitRootLogin without-password
Uncomment PermitRootLogin without-password and modify it to PermitRootLogin yes.
Then restart ssh, sudo service ssh restart. This will allow you to log in as root user
{{o.name}}
{{m.name}}