SAN School Answer #9

This is the function of using port zoning and worldwide name zoning in the same zone set.

a. load balancing
b. mixed zoning
c. mirroring
d. virtualization

The correct answer is:
b. mixed zoning

Zoning is a fundamental technique for SAN management that can be implemented several different ways. In all cases zoning serves to limit users' access to the appropriate storage devices. This increases security and decreases traffic over the network.

Storage resources are usually zoned either at the device level or the LUN level. In device-level zoning each user is restricted to accessing specific physical devices such as RAID arrays or individual disks. Zoning at the LUN level allows the administrator to allocate space in logical units rather than physical chunks. A LUN zone may be spread over several physical devices, often sharing the devices (but not the storage space) with several other zones.

Zoning is a powerful tool for making the most efficient use of storage assets in a SAN. But it must be planned carefully to make the best use of the available storage and the network's bandwidth. Zoning usually makes it harder to shift storage capacity from one group of users (in one zone) to another and making such a switch without rebooting can create security holes since users in both zones may end up with access to the storage space which has been moved.

For more on zoning and how it works, see: