Doctor, It Hurts When I Downgrade Mavericks To Mountain Lion (So Don’t Downgrade Mavericks To Mountain Lion)

There are better ways to spend a rainy Monday in Grand Rapids…

I’m posting this just in case anyone else runs into this problem where you set up an older version of OS X on a partition and then when you try to log in, it does the dissolve, but then immediately returns you to the login screen. tl;dr is “forget about doing Migration Assistant from Mavericks back down to 10.6”, but that’s just what finally worked for me.

Let’s jump back to the beginning of this story: I’m nearly done with a big AV Foundation client project, but we need to run on Mavericks in order to use a one-line call to opt in to pro (HD) codecs; details here. And hey, Mavericks will be the current OS X in a couple weeks. So I updated my main partition to Mavericks and found that the app had some new crashing bugs, caused by the fact that creating an AVAsset now gets its duration much later than it did on Mountain Lion. So I rewrote that to be nice and asynchronous, which I should have done in the first place, but now I want to make sure that it’ll still work in the Mountain Lion case. Whether getting the duration is synchronous or if I’m just winning a race, I want to make sure it works (put another way, maybe the asynchronous approach doesn’t work if I set up the KVO after the duration has already been set, since there wouldn’t be a zero-to-correct-value change to observe in that case).

So, I need a Mountain Lion partition. Fine, I’ve been using one of my HDD partitions as a Mavericks beta, I’ll just downgrade that to Mountain Lion.

FWIW, I name my Macs and their partitions after female characters in Final Fantasy [no, it’s not sexist: my iPhones are named for male characters]. So Yuna is my current Mac OS X on an SSD, and Rikku is an HDD partition with either the latest beta, or a previous OS X. So the story here is that we’re reverting Rikku from Mavericks DP 8 to Mountain Lion

Just running the Mountain Lion “Install Mac OS X” app from the Mac App Store on Mavericks doesn’t work, of course, so I opt for the nuke-and-reinstall route. I wonder now if I could have booted into the recovery partition, but it would have been a 10.9 recovery partition at that point, so I don’t know if that approach would have been able to nuke Rikku and then install an older OS than the one that created the recovery partition.

No, since this is an Early 2008 Mac Pro, I opt for installing Snow Leopard, planning to get up to 10.6.8 so I can run the Mac App Store installer for Mountain Lion. First mistake is that I have an enormous collection of old OS X and iOS betas on DVD, and installed a non-final version of 10.6, which the 10.6.8 updater refused to update.

So, I downloaded 10.6 and put it on a thumb drive — first because it’s faster than slamming the DVD read head all over the place, and secondly because it’s over 6 GB and I don’t seem to have any dual-layer DVD-Rs (and neither did Meijer when I biked over to buy some). Anyways, this works fine and updates me to 10.6. I didn’t want to do the lengthy user migration because I wanted to make sure all the upgrades would work, so I created user “Temporary User” and then upgraded to 10.6.8 with the updater, and then to 10.8. Finally, I ran the Migration Assistant to copy over my stuff from Yuna (my main drive, running Mavericks GM), and then switched to my own account and deleted “Temporary User”.

Next login attempt, this:

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Every time I type my password, the login screen fades out as if it’s logging in, but then returns to stitched-linen-land for another attempt to login. Endless loop. This isn’t a wrong password thing: that would give me the shake animation, and besides I used the Password Assistant utility from the boot drive to reset the password and try again.

Hypothesizing that deleting the user who did the install may have been a mistake, I start over by nuking Rikku, reinstalling 10.6, and then doing Migration Assistant to make myself the only user. That’s the normal scenario and should work, right?


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So I tried some other things at this point, including resetting root‘s password (gets the same login-loop problem as mine), and booting into Safe Mode (stops at about 30% complete, never gets further even after leaving it on all night).

Aside: While I’m working on this, I occasionally drift into the other room to see what’s on TV while I debate waiting out Migration Assistant or just going to bed. Monday Night Football was boring because the Jets are boring, so I drifted into How The Universe Works on Science channel. The episode I saw most of was about supernovae, and I guess we’ve learned a lot more about them since I was in school, because I totally do not remember this story that as soon as a giant star fuses iron atoms, it’s doomed, because they won’t fuse and the energy that’s trying to fuse them isn’t pushing out the outer layers, and then gravity wins. Also hadn’t heard the other part of the story, that atoms smashing together during the collapse creates all the heavier elements. So, that made staying up late worth it, because Mac OS X sure didn’t. Also, how soon until the new Cosmos premieres?

So, this morning, after all the hours I’ve thrown into this, I hypothesize that maybe doing Migration Assistant from 10.9 to 10.6 doesn’t work, and try setting up my account from scratch. I won’t have my mail or other conveniences without some hassles, but the whole point of this partition is brief trips in for compatibility testing, not long stays, so I’m willing to live with it.

Mercifully, this works. At least as of the last of three update reboots, I was able to get right into Rikku. Actually, the partition is running in single-user mode, so I’m not hitting the login screen and frankly, I don’t want to jinx it.

So, moral of story (I think) is that you shouldn’t plan on migrating users / documents / applications / settings from Mavericks GM back down to 10.6 when you need to downgrade a partition.

Comments (2)

  1. dandipaola

    I got lost a few times through out your post … it’s my ADD. BottomLineDidYouSuccessfullyMigrateFromTheDeadlyMavericksBackTo-10.8? If not I’m screwed. If you did please lay out process in3 simple steps how the hell you did it PLEASE TIA signed, A 20+ year IT MONKEY user who was TOO stupid to back up his own drive

  2. Well, the point of the last two grafs is that I did get 10.8 installed, but without migrating my user info over. So I’ve created a new account on the 10.8 partition, but it doesn’t have any of my settings, and since the permissions are different, it can’t get into the home folder of my user on the Mavericks partition. Ugh.

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