A question we receive a lot is what kind of zoning should be implemented for our storage solution? The answer is usually really short and simple: at least single initiator zoning.
Single initiator zoning is something we have always recommend in the field (VMware PSO Consultants/Architects) and something that is clearly mentioned in our documentation… at least that’s what I thought.
On page 31 of the SAN Design and Deploy guide we clearly state the following:
When a SAN is configured using zoning, the devices outside a zone are not visible to the devices inside the zone. When there is one HBA or initiator to a single storage processor port or target zone, it is commonly referred to as single zone. This type of single zoning protects devices within a zone from fabric notifications, such as Registered State Change Notification (RSCN) changes from other zones. In addition, SAN traffic within each zone is isolated from the other zones. Thus, using single zone is a common industry practice.
That’s crystal clear isn’t it? Unfortunately there’s another document floating around which is called “Fibre Channel SAN Configuration Guide” and this document states the following on page 36:
- ESX Server hosts that use shared storage for virtual machine failover or load balancing must be in one zone.
- If you have a very large deployment, you might need to create separate zones for different areas of functionality. For example, you can separate accounting from human resources.
So which one is correct and which one isn’t? I don’t want any confusion around this. The first document, the SAN Design and Deploy guide is correct. VMware recommends single initiator zoning. Of course if you want to do “single initiator / single target” that would even be better, but single initiator is the bare minimum. Now let’s hope the VMware Tech Writers can get that document fixed…