Imagine you've grown to love this storage area network (SAN) stuff so much that it's reproducing like rabbits throughout your company! Things are starting to get out of hand again. You have little islands of SANs in multiple buildings, and it's hard to manage all those separate SAN environments.
SAN management provides an exciting capability: You can access and control a company's storage resources from a centralized administrative desk — using a single management console — and replicate data between locations for disaster recovery. One reason all this is possible: You can connect SANs across a distance.
Having SANs in multiple places is a good thing, because you connect them and use a remote location as a backup or recovery site for your company. You can actually make the gloom-and-doom disaster-recovery guys happy.
This chapter covers methods of connecting SANs. It also covers the fundamentals of choosing the correct links between SAN islands to do the job right. This chapter also touches a bit more on the iSCSI protocol, some virtualization techniques, and virtual storage pooling. (For more on virtualization and storage pooling, see Chapter 15.)
A SAN island is a storage area network that is physically isolated in a single location and managed as a separate physical entity, as shown in Figure 8-1.
Figure 8-1. SAN islands are separate entities. ...