Auto-upgrade From Catalina to Big Sur Best Suggestions

[ABillings]

I know this question has been beat to death since the rollout of Big Sur, but I need a little guidance. We're new to Jamf Pro and "just ok" as Apple admins. What we're looking for is something similar to a "feature update" in SCCM or Intune where we can apply the Big Sur upgrade to Catalina machines. All users are admins on their machines at this point, as we literally just completed enrollment. I have Big Sur as a .pkg and was thinking we could deploy it through policy, but 12 GB is probably a little large to pass over the wire. Was hoping there was a tool in Patch Management, but as I've learned Patch Management in Jamf sucks, as its more Patch Reporting than anything. Is there a way to call down Big Sur to a machine, auto install, and just let the user reboot to finalize install?

[PaulS_CUKL]

You can create a policy to cache the pkg on to the local machines in the background and create a smart group that detects it once the down load has completed and create a policy scoped to that group to install it

[ABillings]

I currently have a script: /usr/sbin/softwareupdate --fetch-full-installer --full-installer-version 11.2.3
It's setup in a policy that I tested, at the moment triggered at check-in and ongoing. That seems to wake up Big Sur installer on a test machine I have running 10.15.7. So you're saying that I should create a smart group that scopes machines that have 10.15.7 (that's currently what all our Catalina users are on), applies that script to them to call down Big Sur, and then apply another policy to install Big Sur. Any suggestions on what that install policy looks like and how does it get applied to those machines scoped out by the smart group?

[jcarr]

See the 'Upgrading instead of erasing' note at the end of this post.

[ABillings]

@jcarr you're saying that this is the script to use to install Big Sur on those machines scoped by the smart group after Big Sur has been downloaded to those machines? '/Applications/Install macOS Big Sur.app/Contents/Resources/startosinstall' --agreetolicense --forcequitapps

[jcarr]

@ABillings Correct. Both the erase and upgrade options require the full macOS installer to be downloaded, but the upgrade option omits the '--eraseinetall' and '--newvolumename' options.