This came up today and I want to make sure it's clear.
Remember the "deferred update" I spoke about in my "Upgrade to AK8" entry just a bit ago? It's important to understand that this deferred update changes the way replication works. It is necessary that systems with the deferred update applied only replicate with other systems that have also had this deferred update applied. So if you apply it, your system can NOT replicate with ANY other system that has NOT had it applied, even if that other system is running AK8!!! Got it???
Remember, we do have a new version of the 2011 code for the older systems that do not want to upgrade to AK8. This 2011.1.8 code ALSO HAS this same deferred update in it. So, if you upgrade your system to AK8, and then apply the deferred update, and you have another system running either 2011.1.8 or AK8, you can replicate with them again once they apply the deferred update for multiple initiator groups. Yes, even if you're not using LUNs. Here is what it looks like if you try. It will fail.