For most organizations, it is impractical to attempt to rationalize user accounts across the enterprise to achieve a single global UID for each user. For example, most organizations have multiple identity stores already in use on their current UNIX platforms. These identity stores may include LDAP directories, NIS or NIS+ domains, and local /etc/passwd and /etc/group configuration files. With these multiple identity stores, it is common for a single user to have a different user name, UID, group memberships, or other attributes defined for different computers.
Zones allow you to import the information from these legacy identity stores without consolidating the multiple profiles that each user may have. For example, a single user might have an account in a UNIX LDAP directory, another defined in a NIS domain, and one or more local /etc/passwd files. Zones enable the profiles from these different identity stores to map to a single Active Directory user account without changing the user profile defined in each of the legacy directories. By keeping the profiles intact, the user’s file ownership and log in permissions are not affected by the migration to Active Directory, making the transition from a legacy system to Active Directory more transparent to end‑users and less of a management burden for the deployment team.