Single initiator zoning
Each Fibre Channel zone created should contain a single initiator (host HBA port) and all applicable storage
target ports. In other words, each HBA port on the host requires its own zone; containing itself and the
applicable storage ports. For resiliency and availability, two fabrics should be used, each containing half of the ports on each host and half of the ports on each storage processor (SP) on the Dell EMC Unity array
https://www.delltechnologies.com/resources/en-us/asset/white-papers/products/storage/h16391-dellemc-unity-storage-vmware-vsphere.pdfWhen 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.
http://www.yellow-bricks.com/2010/03/04/single-initiator-zoning-recommended-or-not/In principle single hba / target zoning, for obvious reasons.
But you are using a DS-6520B, so you should be able to upgrade to FOS 7.4. And FOS 7.4 can use "peer zones". these are zones, with single initiator / multiple targets. This is all described on page 351 of the FOS 7.4 Administrator guide, downloadable from the EMC support site.
https://www.dell.com/community/Connectrix/Zoning-Best-Practice/td-p/7064491Using Zoning with Fibre Channel SANs
With ESXi hosts, use a single-initiator zoning or a single-initiator-single-target zoning. The latter is a preferred zoning practice. Using the more restrictive zoning prevents problems and misconfigurations that can occur on the SAN.
For detailed instructions and best zoning practices, contact storage array or switch vendors.
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.storage.doc/GUID-E7818A5D-6BD7-4F51-B4BA-EFBF2D3A8357.htmlEach Fibre Channel zone created should have a single initiator (HBA port) and multiple targets (SC Series
front-end ports). Each HBA port requires its own Fibre Channel zone that contains itself and the SC Series
front-end ports. Independent zones should be created for each HBA installed in the host.
Dell EMC SC Series: Best Practices with VMware vSphere
https://downloads.dell.com/manuals/common/sc-series-vmware-vsphere-best-practices_en-us.pdf
