You need to use the usermod command to lock and disable user account. The -L option lock user’s password by putting a ! in from of the the encrypted password. To disable user account set expire date to one or 1970-01-01.

How do I unlock a Linux account?

How to unlock users in Linux? Option 1: Use the command “passwd -u username”. Unlocking password for user username. Option 2: Use the command “usermod -U username”.

Can you disable the root account in Linux?

The simplest method to disable root user login is to change its shell from /bin/bash or /bin/bash (or any other shell that permits user login) to /sbin/nologin , in the /etc/passwd file, which you can open for editing using any of your favorite command line editors as shown. Save the file and close it.