6120XP to 6248UP Upgrade - Port remap require chassis re-ack?

Question

According to the upgrade guide, step 14f, a chassis re-acknowledgement is required when you change the FC port mapping.  Can anyone confirm that this is valid?  I ask because at this point in the steps the server ports are still down so no chassis is technically connected so why would a re-acknowledgement be required?  It says a chassis re-acknowledgement is disruptive and I thought an upgrade from a 6120XP to 6248 would be non-disruptive.
Any clarification would be excellent. 
Thanks,
-Jason
Upgrade guide: 
http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/sw/upgrading/from2-0/to2-0MR/b_UpgradingCiscoUCSFrom2-0To2-0MR/b_UpgradingCiscoUCSFrom1-4To2-0_chapter_0101.html#d8429e24a1635 

Answer 1

Hi Jason
I think this comment is very misleading.
I don't know a single UCS installation that is using LAN and/or SAN pin groups.
The only reason to do a chassis ack: if you change the server ports connecting the IOM in the chassis.
No chassis ack necessary if you change FC uplink ports assignments.
Walter.
Step 14   (Optional)Remap UCS 6100 fabric interconnect FC ports 2/1 to 2/4 on a N10-E0440 expansion module or any slot 3 ports onto the new fabric interconnect expansion module.
Use UCS Manager to delete the ports on the subordinate fabric interconnect that you will need to move within the configuration.
For each port you have just deleted, create new ports on either slot 1 or slot 2. These ports must use the same port type definitions as the old ports, but will use different port numbers.
For recently moved Ethernet server ports, reconfigure the associated service profile to use the new port number for the appropriate LAN pin group.
For recently moved uplink Ethernet ports, reconfigure the port channel settings to use the new ports.
For recently moved uplink FC ports, reconfigure the associated service profile SAN pin group to use the new ports.
Re-acknowledge chassis for blade servers and fabric extender for rack servers.This will be disruptive to traffic, but is necessary in this specific scenario.