SAN zoning is an interesting concept and it gains importance once your SAN includes more than a couple of dozen devices. During the early days of SAN storage, there were many debates about whether SAN zoning was needed in the first place as a Fibre Channel (FC) SAN standard and even still, SAN zoning standards are evolving. So, in order to understand this properly, lets take a closer look.
What is SAN Zoning?
SAN zoning is basically a service for grouping the devices in a SAN into logical segments in order to control and monitor communications between the devices.
When SAN zoning is configured, only the devices in the same zone can communicate with each other. However, devices can indeed be members of multiple zones which offers greater flexibility in setting up SAN communications.
SAN storage is divided into logical units that are assigned LUNs (Logical Unit Numbers). A unit can really be based on anything, from a drive’s partition to even an entire RAID set. Each port on a storage node is mapped to many LUNs. This is important as when zoning isn’t enabled, every server in a SAN storage can mount all the LUNs that it sees. Zoning, however prevents this widespread mounting by actively controlling which devices can communicate with each other and which cannot. As a result, this isolates the devices into logical zones while also enabling each device to participate in multiple zones as well.
Benefits of SAN Zoning
Zoning promotes fabric stability, security and efficient management which is really needed in a SAN storage solution. While it is true that smaller SAN environments can indeed function without zoning, the approach enables all the devices to interact with each other which as a result, can really affect the performance even with smaller SANs.
It is actually discouraged to implement SAN without zoning as it helps in providing high availability. This is because if all the devices are grouped into one large zone, each time a device is added or removed from the fabric, it can cause disruption.
Zones can be organized into different zone sets. Zone sets can help enforce more security across the many devices that are connected through a fabric. Zone sets can also help in performing backups, device testing and other forms of maintenance.
Conclusion
SAN storage is a great storage solution for businesses but it can be better implemented by using SAN zoning. IT teams should implement SAN zoning even if it wasn’t in their plans initially so that they can enjoy the benefits of SAN zoning and can gain full benefit from their SAN storage solution.
