This option determines the basic operating mode of a Samba server and is one of the most important settings in the smb.conf file. The default is server role = auto, as causes Samba to operate according to the setting, or if not specified as a simple file server that is not connected to any domain. The alternatives are server role = standalone or server role = member server , which support joining Samba to a Windows domain, along with server role = domain controller, which run Samba as a Windows domain controller. You should use server role = standalone and if you want to mainly setup shares without a password (guest shares). This is commonly used for a shared printer server. SERVER ROLE = AUTO This is the default server role in Samba, and causes Samba to consult the parameter (if set) to determine the server role, giving compatible behaviours to previous Samba versions. SERVER ROLE = STANDALONE If is also not specified, this is the default security setting in Samba. In standalone operation, a client must first "log-on" with a valid username and password (which can be mapped using the parameter) stored on this machine. Encrypted passwords (see the parameter) are by default used in this security mode. Parameters such as and if set are then applied and may change the UNIX user to use on this connection, but only after the user has been successfully authenticated. SERVER ROLE = MEMBER SERVER This mode will only work correctly if net 8 has been used to add this machine into a Windows Domain. It expects the parameter to be set to yes. In this mode Samba will try to validate the username/password by passing it to a Windows or Samba Domain Controller, in exactly the same way that a Windows Server would do. Note that a valid UNIX user must still exist as well as the account on the Domain Controller to allow Samba to have a valid UNIX account to map file access to. Winbind can provide this. SERVER ROLE = CLASSIC PRIMARY DOMAIN CONTROLLER This mode of operation runs a classic Samba primary domain controller, providing domain logon services to Windows and Samba clients of an NT4-like domain. Clients must be joined to the domain to create a secure, trusted path across the network. There must be only one PDC per NetBIOS scope (typcially a broadcast network or clients served by a single WINS server). SERVER ROLE = CLASSIC BACKUP DOMAIN CONTROLLER This mode of operation runs a classic Samba backup domain controller, providing domain logon services to Windows and Samba clients of an NT4-like domain. As a BDC, this allows multiple Samba servers to provide redundant logon services to a single NetBIOS scope. SERVER ROLE = ACTIVE DIRECTORY DOMAIN CONTROLLER This mode of operation runs Samba as an active directory domain controller, providing domain logon services to Windows and Samba clients of the domain. This role requires special configuration, see the Samba4 HOWTO security realm encrypt passwords AUTO ACTIVE DIRECTORY DOMAIN CONTROLLER