Explanation
Samba cannot use /etc/passwd and /etc/shadow directly because they store passwords in a different format than CIFS. CIFS passwords are encrypted using a one-way hash function, while Unix passwords are encrypted using a two-way cipher. Therefore, Samba needs a separate password file that stores the CIFS passwords in a compatible format. This file is usually called smbpasswd and can be created or updated using the smbpasswd command123 References:
Chapter 9. Users and Security - Samba
smbpasswd - Samba
Chapter 20. samba authentication - linux-training.be
Chapter 9. Users and Security - Samba3
Chapter 9. Users and Security - Samba
