Software upgrades on HA Pairs?

[Wes Schochet]

I am working on a plan to convert some of my existing 5508s to be HA pairs.  I like the redundancy i have now with multiple controllers, but don't necessarily like buying two licenses for every AP.  I am trying to determine the downside to the HA mode.  I am trying to figure out what a code upgrade looks like for a redundant pair.   Currently, because I have 2 licenses for each AP, I have this process:

1. Load new code onto both controllers (no reboot here)

2. move the APs from controller A to controller B,

3. Reboot controller A to new code

4. Predownload new code from controller B to APs

5. Slowly move APs back to controller A so that there is no real outage.  Clients move to adjacent APs as each AP is individually rebooted. 

Is there a way I can take an HA member out of service, upgrade it and move the APs to it before doing the other HA member?  Or does the whole HA pair have to be down to facilitate a code upgrade?  Curious to hear what others are doing.

Thanks

[Leo Laohoo · Accepted solution]

Before you convert the WLC to HA, make sure all the bootstrap have been upgraded.  If you have any certificates and/or web-auth pages, make sure they are loaded to both before you tie them up into an HA.

Next, your license for the 2nd unit.  Send an email to licensing@cisco.com and provide the HA serial number.  Tell them you want to convert this unit to HA SSO.  They'll send you further instructions. 

Ok, now the HA bit.  Choose a firmware, either 7.4.121.X or 7.6.110.X.  Don't choose anything else.  

Read through the High Availability (SSO) Deployment Guide and pay close attention to mandatory requirements especially the requirement that both 5508 must be physically connected via the RP port.

Let us know how you go.

[Wes Schochet]

Thanks Leo -

I did find the HA deployment guide very helpful.  My concern here is downtime.  Although it won't be much, I don't think I can make it transparent to the users like I do using the procedure above.  I guess it'll come down to the cost and whether it's worth it or not.

[Leo Laohoo]

Downtime to upgrade the WLC firmware alone takes about 25 to 40 minutes.  

What I do is upload the firmware to the HA SSO pairs and then invoke the pre-download to all the APs.  Then I schedule the WLC pairs to reboot at 4 am.

Thanks for taking the time to rate our posts.   

[Leo Laohoo]

Ok, here's the beauty of HA SSO.  

Once you've got both unit into an HA SSO, if you need to upgrade the code, you upgrade only ONCE.  The active controller will push future codes (including bootstrap) to the standby controllers.  

After the code has been pushed, you can elect to pre-download the software to the AP before you hit reboot.