Specifications

Chapter 1 Directory Services with Open Directory 27
About Shared Directory Domains
Although Open Directory on any Mac OS X computer can store administrative data in
the computer’s local directory domain, the real power of Open Directory is that it lets
multiple Mac OS X computers share administrative data by storing the data in shared
directory domains.
When a computer is congured to use a shared domain, administrative data in the
shared domain is also visible to applications and system software running on that
computer.
If Open Directory does not nd a user’s record in the local directory domain of a
Mac OS X computer, Open Directory can search for the user’s record in any shared
domains the computer has access to.
In the following example, the user can access both computers because the shared
domain accessible from both computers contains a record for the user.
Shared
directory
domain
Local directory
domain
Local directory
domain
Log in to
Mac OS X
Connect to Mac OS X
Server for file service
Shared domains generally reside on servers because directory domains store
extremely important data, such as the data for authenticating users.
Access to servers is usually tightly restricted to protect the data on them. In addition,
directory data must always be available. Servers often have extra hardware features
that enhance their reliability, and servers can be connected to uninterruptible power
sources.