CX4-960 Open Replicator to Symmetrix RSCN question

Welcome to the forums Neilhopwood !

RSCN's will propagate withnig the same fabric, so if you zoned these 4 FA and 4 SP ports in a separate fabric with just these 8 ports (2 fabrics of course with 4 ports in each fabric), there's no problem there. If you zoned the FA's and SP's in the same fabric as your hosts RCSN's could be something to worry about. If you're zoning accross sites over dark fiber and everything on 1 side is in the same fabric as on the other side and bulldozer might rip a cable and trigger a fabric split. An RSCN will follow. If the cable is repaired (or worse: if it's a on/off/on/off/on/off contact) another RSCN will follow again because of the fabric merge. I doubt a change on the DMX will trigger an RSCN. Once the storage ports are actually connected to the SAN no more RSCN's should follow, unless the DMX is rebooted or something

I am not sure what the concern is about RSCNs? As I understand they are part of the normal operation of a switch and looking at my switches statistics they happen on a regular basis when the fabric changes. RSCNs are a standard I believe for all FC switches and should not affect host/storage ports. What is the issue you are concerned about?

This is a dual fabric environment.
The customer is very concerned about anything that can impact performance of a particular suite of applications. Recently we've noticed Symm config changes are impacting performance and causing timeouts within this suite of apps - albeit impacts of less than 10 secs but impacts never the less. I want to be able to re-assure them that there will be no chance of propagation.

But are you sure that the symm config changes are triggering RSCN and that those RSCN are actually the cause of the timeouts?

If you have not already I would open up a case with EMC to look into this.