WLC HA Pairing plus N+1 redundancy AirOS upgrade

[daswann]

At one of our sites we have 3 8540's. Two are in an HA SSO paring with the 3rd in N+1. I need to upgrade the OS on all three. What is the best procedure to do this. Should I upgrade the Paring first then N+1 WLC. The goal of course doing it with the least downtime as possible. The code today is 8.3.133.0. I was thinking of upgrading the pair first with the N+1 disconnected from the cluster then upgrade the N+1 and add it back in? 

Thanks in advance! 

[Scott Fella]

I would move all the ap's to the N+1 controller, then upgrade the SSO.  Once done, move a few back and test to make sure everything is fine.  Once you verified that, then you can move all the ap's back to the upgraded SSO and upgrade the N+1.  Either way, you would need to move the ap's to either the N+1 first or the SSO.  Doesn't really matter which you want to do first as long as the one you want to upgrade doesn't have an ap's.

[daswann]

Thank you Scott,

I like the idea of using pre-image download to both the APs and the controller then doing a swap, we have 921 access points at this location and I'm trying  to save as much time as possible (Hospital)  that way too. Your thoughts on adding this to the procedure you recommended please. This will be done during a maintenance window so I'm trying to calculate the approximate time to do this for management. 

Thank You,

[Scott Fella · Accepted solution]

Pre-download is something you can do and like a recent post on the wireless forum, Leo mentioned a quicker way to upgrade 3702’s only. I always tell folks that you need to schedule downtime to take into account troubleshooting and validation.

[daswann]

Thank you Scott,

I found out that it doesn't work with the old 2502i the hard way. I do have a lot of 3702i in the network so I will try it again when I upgrade those controllers.