06-27-2013 03:27 PM
Greetings bryan_a_wilson. This is a common topic on the community pages and doing a quick search will result in some good information. Here is one for example,..
Additional info to consider...
When a new switch is added to the fabric, it automatically takes on the zone configuration information from the fabric. Adding a new fabric that has no zone configuration information to an existing fabric is very similar to adding a new switch. All switches in the new fabric inherit the zone configuration data. If the existing fabric has an effective zone configuration, then the same configuration becomes the effective configuration for the new switches. If a new switch that is already configured for zoning is being added to the fabric, the zone configuration should be cleared on that switch before connecting it to the zoned fabric. When a change in the configuration is saved, enabled, or disabled according to the transactional model, it is automatically distributed to all switches in the fabric (by closing the transaction), preventing a single point of failure for zone information. Zone changes in a production fabric can result in a disruption of I/O under conditions when an RSCN is issued because of the zone change and the HBA is unable to process the RSCN fast enough. Although RSCNs are a normal part of a functioning SAN, the pause in I/O might not be acceptable. For these reasons, you should perform zone changes only when the resulting behavior is predictable and acceptable. Ensuring that the HBA drivers are current can shorten the response time in relation to the RSCN.