FYI - High Sierra now an *UPDATE* on Macs running OS X 10.10 Yosemite

[pcrandom]

[Hopefully this isn't something pre-announced that I just missed, but I did try to search for it first.]

We have a restriction on the the macOS High Sierra Installer and noticed starting on Tuesday a spike in the number of machines violating the restriction. All the Macs were running OS X 10.10.5, and I noticed that they had run Software Updates recently. When I check for updates the Macs, I see the following:

softwareupdate --list --all
Software Update Tool
Copyright 2002-2012 Apple Inc.

Finding available software
Software Update found the following new or updated software:
   * Install macOS High Sierra- 
    macOS High Sierra ( ), 5106655K [recommended]

Apparently earlier this week Apple made High Sierra an UPDATE rather than an upgrade. This change appears to only be on OS X 10.10 Yosemite (presumably 10.10.5), as I had checked for this on OS X 10.9 Mavericks and OS X 10.11 El Capitan, and neither show "Install macOS High Sierra" when checking for updates.

If you don't want your Yosemite Macs to automatically upgrade to High Sierra, you can run this command: softwareupdate --ignore "Install macOS High Sierra" This will prevent High Sierra from appearing in the Updates tab of App Store.app and from installing when running updates.

[pcrandom]

Of course @gregneagle has it covered: https://managingosx.wordpress.com/2018/04/11/unwelcome-apple-surprise/

[cbrewer]

I'm glad Apple is doing this. Yosemite is end-of-life on security updates. I'd rather see them get updated than get compromised.

[pcrandom]

@cbrewer I don't disagree, but we're not ready to move to High Sierra yet in our environment. We've been upgrading older OSes to Sierra.

[c_archibald]

If Windows can do it with 10, Apple will do it too. Odd that 10.11 doesn't get the same treatment.

[rtrouton]

This is not an automatic upgrade, and is similar to behavior seen on El Capitan, where the Sierra installer was pushed:

https://derflounder.wordpress.com/2016/10/03/managing-the-automatic-download-of-the-macos-sierra-ins...

[pcrandom]

Thanks @rtrouton. I haven’t tested it myself yet to see the prompting after the installer is downloaded, but if I recall, the Sierra installer download process was not transparent, you didn’t see it using softwareupdate and you couldn’t block it individually using --ignore like you seem to be able to with this one. Will test tomorrow.

[pcrandom]

Additional details after testing: If I run softwareupdate --download --all it downloads the installer to /Library/Updates and leaves it there but does not run the update. If I then run softwareupdate --install --all (or click the Update button in App Store.app) then it puts Install macOS High Sierra.app in /Applications and launches it. So, like Rich said, not an automatic upgrade.

Interestingly, after the installer is no longer in /Library/Updates or in /Applications (I deleted it), if I run softwareupdate --download --all it no longer lists it as an available update.

[chris_kemp]

Seems like a good thing to me, 10.10 is pretty long in the tooth at this point. Since it's not going to be patched for the Meltdown & Spectre vulnerabilities in particular, it's really in your interest to upgrade away from it.