smbpasswd is the Samba equivalent of the system's passwd, it allows
for the management of Samba user accounts.
Add a user
To add a user, use smbpasswd with the -a option, and the username as
the only required parameter, e.g:
smbpasswd -a obiwan
The very first time that you will run smbpasswd it will warn that a
user database does not yet exist. This is normal, and smbpasswd will
generate that database.
Change a password
Users can change their own passwords, and root can change any other
user's password. If the Samba server authenticates users against a
remote server, the server can be defined with the -r option.
For example, when used with a local user database (i.e. in conjunction
with a security = User setting in [Global]), a user can change
their password with just:
obiwan@server ~ $ smbpasswd