Serv-U File Server makes use of several concepts that help you understand how to configure and administer your file server as a single, hierarchical unit. Serv-U File Server contains four related levels of configuration: the server, the domain, the group, and the user. Only the group level is optional. The other levels are mandatory parts of the file server.
The server is the basic unit of Serv-U File Server and the highest level of configuration available. The server represents the file server as a whole and governs the behavior of all domains, groups, and users. Serv-U File Server contains a set of default options that can be overridden on a per-setting basis. The server is at the top level of the hierarchy of configuring Serv-U. Domains, groups, and users inherit their default settings from the server. Inherited settings can be overridden at each of these lower levels. However, some settings are exclusive to the server, such as the PASV port range.
A server can contain one or more domains. A domain is the interface through which users connect to the file server and access a specific user account. The settings of a domain are inherited from the server. A domain also defines the collection of settings that all of its groups and user accounts inherit. If a server setting is overridden at the domain level, all the groups and user accounts that belong to the domain inherit the domain value as their default value.
The group is an optional level of configuration that can make it easier to manage related user accounts that share many of the same settings. By using a group, you can make changes that propagate to more than one user account instead of having to manually configure each user account separately. A group inherits all of its default settings from the domain it belongs to. A group defines the collection of settings inherited by all users who are members of the group. Virtually every user level setting can be configured at the group level, or can be overridden at the user level.
The user is at the bottom of the hierarchy. It can inherit its default settings from multiple groups (if it is a member of more than one group) or from its parent domain (if it is not a member of a group, or the group does not define a default setting). A user account identifies a physical connection to the file server and defines the access rights and limitations of that connection. Settings overridden at the user level cannot be overridden elsewhere and are always applied to connections authenticated with that user account.
Contrary to groups, a user collection does not offer any level of configuration to the user accounts they contain. Instead, a user collection offers a way to organize users into containers for easy viewing and administration. For example, collections can be created to organize user accounts based on group membership. User collections must be maintained manually when user accounts change group membership.