We're about to undertake the 8.2 -> 8.3 upgrade. I understand that failover config will not work if the pair has different memory. For those that have done this already, what was your plan on inserting the new memory?? Obviously, we want to minimize downtime.
We just did this...here's what I did
First, upgrade the ASDM (on both units) to the latest version (6.31) before starting on either unit. The ASDM is backwards-compatible, so there's no problems using it with 8.2. Then follow these steps:
1. Turn the primary unit off. The standby unit will take over the duties.
2. Upgrade the memory and reinstall in the rack but do not power the unit yet.
3. Power off the standby and power up the primary unit. The only downtime is the primary unit rebooting.
4. Upgrade the memory in the standby unit, reinstall in the rack and power up.
After both units are back up and running, I did the 8.3 upgrade through ASDM and changed the boot directory to the new version. Then it's just a simple reboot of both units to use the new version. I was suprised at how easy the process was.
These steps should do the trick to do hitless upgrade on a failover pair with memory upgrade.
1. Install the image on one unit (say secondary/standby) and set the boot variable, and then power it off.
2. Install the memory, and then power unit back on.
3. It will boot up and convert the config and then do the failover config sync.
at this point it will bring the config from the active unit which will be 8.2 config but it will convert it as it receives.
4. Once complete, this unit will be running 8.3 as a standby.
5. We can make it Active and then perform the same functions on the peer unit.
Regarding nat statements that may not convert over properly, we did have some known issues that were solved in 8.3.2 code.
Pls. read open and resolved caveats are here:
I have listed some related to NAT which are resolved in the 8.3.2 code
CSCtf57830 Incorrect real ip translation of ACE after 8.3.1 upgrade