In a storage area network (SAN), zoning is the allocation of resources for device load balancing and for selectively allowing access to data only to certain users. Essentially, zoning allows an administrator to control who can see what in a SAN.
Zoning is done using a structure similar to that of a computer file system. A zone is the equivalent of a folder or directory. Zoning can be either hard or soft. In hard zoning, each device is assigned to a particular zone, and this assignment does not change. In soft zoning, device assignments can be changed by the network administrator to accommodate variations in the demands on different servers in the network.
The user of zoning is said to minimize the risk of data corruption, help secure data against hackers, slow the spread of viruses and worms, and minimize the time necessary for servers to reboot. However, zoning can complicate the scaling process if the number of users and servers in a SAN increases significantly in a short period of time.