Appendix B. Case study: IBM Global Storage Architecture 319
deployed in Poughkeepsie NY, with a submaster at each GSA File site. Two
geographically dispersed submasters were located in Europe and Asia. The
master accepts all changes to the directory and pushes them to the geography
submasters as well as the North American site submasters. The site submitters
then push changes to the end-user replicas at each site.
The master server is a single point of failure for the system, but only for changes
to the LDAP directory. If a user at a specific cell cannot reach the master on the
network, or the master is down, that user can continue to use the file system with
data located on their local replicas but cannot change their password, manage