I finally broke and bought a C8 Pro that should be on its way shortly. I am going to migrate my C8 to the C8 Pro then migrate my C7 to my C8. I know that I have seen at least one thread discussing the perils & pitfalls of that exact situation but can't find without any unique search words. Can anyone who might have participated in that thread (or threads) point me in right direction?
I currently have all of my Zigbee & Zwave on C8 and all of my LAN or internet-related things running on the C7. I am not using Matter for anything nor have any intention of doing so.
I unfortunately don't remember that thread, and not sure what the pitfall(s) would be other than the same pitfalls that can affect any migration.
As long as you do the migrations one at a time, and ensure things are working normally across the board after the first migration before continuing to the second, things should "just work."
Main potential issues should be the usual - moving your IP reservations from the old hubs to the new hubs, turning off and unplugging the retired hub(s) as you proceed, ensuring hubs are on the same/latest platform version, etc.
Maybe someone else will remember any special "stumble points" around the scenario.
...turning off and unplugging the retired hub(s) as you proceed...
Aha...that may be the issue, as you'll need to have the C8 you migrated from up and running to migrate to it from the C7. Seems like you'd need to do Zigbee & Z-Wave radio resets after the migration to the C8-Pro is confirmed live/running as expected w/C7. Then bring the C8 back online & quickly do the radio resets so your hub isn't calling out to the devices now on your C8-Pro. Maybe that was the area of concern...
What if you pulled the antennas on the C8 while resetting the radios? It's not necessarily good for the radios to operate without antennas but I would think the short duration wouldn't be of any great concern.
I've done this 'leap frog' migration once, a while ago. I migrated a pair of C8 to a pair of Pro and then migrated my Development hub (at the time a C7) to the C8.
I encountered zero issues, as I had hoped for. I followed the general migration advice that was available at the time. Get a good cloud backup of the C8, power it off. Then get the new C8Pro registered and on a matching platform. Then use the Migrate option (in Backups) to pull the cloud backup into the Pro. At that point, it should all just work. It's (obviously) critical to test that everything really is working. Recovery at this point is trivial... you just power off the Pro, power on the C8 and it will pick up right where it left off, allowing for a 2nd try.
My concern would be not having a "fall back". I kept my C7 as a security blanket for a month, just in case. My migration was uneventful, outside of needing to pair a few Zigbee devices. Before my cloud migration backup, I did a reboot w/ DB rebuild and was sure to disbale all LAN integrations and uninstall nonessential apps.
The only thing I've noticed is Z-wave (Zip) on the C8pro, for ME, seems a bit more quirky. Nothing huge but more failures with automations, maybe 2 per week as compared to my C7 with maybe 2/month.
I did have a better antenna on the C7(did the mod) and tried putting that on the C8, but it's about the same. It seems the C8 pro kinda freezes, but usually comes back after a few minutes. I can't find anything in the logs.
Phewf, long winded way to say you'll be fine, outside of minor or maybe zero, hiccups.
The only migration issue I remain concerned about is that when a C7 or earlier is migrated to a C8 pro you won't be able to use Z-Wave LR without resetting the radio and re-adding all devices. Even then, it appears that restoring the radio from a cloud bakup could break things again (not sure of this however). Problem is that this is essentially a Silicon Labs issue with no short term fix identified.
I did a similar migration, C8 to C8 Pro. I was going to move the few C7 apps and devices to the C8. In the end I decided to mothball the C8 and leave the C7 in service and continue to share those via mesh. I couldn't see any advantage to moving them to the C8. That would leave the more capable C8 available for future Hubitat play or of more value to sell.
Fortunately, I am going from C-8 to C-8 Pro. The C-7 doesn't have any radios enabled.
My plan is to migrate the C-8 to C-8 Pro and let run for a month or so before doing the C-7 to C-8 just to ensure everything is stable. Similar to what you said, the stuff I have running on my C-7 doesn't benefit much by moving to a C-8.
Thank you to all for comments. This moring, I got the notice that the C-8 Pro was shipped and shipped from same city I am in so should be here soon!
It was a buttery smooth transition from the C8 to the C8 Pro. The C8 is now going to sit on the sidelines for a month or so until I am ready to use it to replace the C7.
