Downgrading operating systems

[scofopolis]

Just upgraded to high sierra, but some plugins in my DAW (live 9) are not working properly.

Problem is - I don't think I had a time machine running (is there a way to check this? To check if I indeed have a backup of when I was running Yosemite)?

What are my options? Do i wipe and reinstall yosemite and subsequently reinstall all my apps etc...?

Thanks in advance for the help!

 

[chscag]

If you have no Time Machine or a CCC backup, then you'll need to get hold of a copy of whatever version of macOS you were running before upgrading to High Sierra. Check the Mac App Store for your purchases.

 

[Bart Kela]

JProblem is - I don't think I had a time machine running (is there a way to check this? To check if I indeed have a backup of when I was running Yosemite)?

If you open up the Time Machine pane in System Preferences, it will tell you the dates of the oldest and last backups.

If you enter Time Machine, you will see the dates of all backups on the right hand side if you put your cursor over one of the hashmark indicators.

 

[scofopolis]

If you open up the Time Machine pane in System Preferences, it will tell you the dates of the oldest and last backups.

If you enter Time Machine, you will see the dates of all backups on the right hand side if you put your cursor over one of the hashmark indicators.

thanks! So yea, no time machine backup.

So I wipe and reinstall Yosemite (for example, if this is the version i want to revert back to)

 

[Fishrrman]

OP wrote:
"So I wipe and reinstall Yosemite (for example, if this is the version i want to revert back to)"

That's pretty much what you need to do.
Be sure to first ERASE the internal drive using Disk Utility to HFS+ with journaling enabled.

I know the advice I'm about to offer doesn't help now, but...
... NEXT TIME you want to try a major system upgrade, do this first:
1. Download CarbonCopyCloner (FREE to download and use for 30 days)
2. Create a bootable clone of your internal drive on an external drive.
3. THEN, if you want to "go back", it's a trivial matter to do this:
a. Boot from the cloned backup
b. Erase the internal drive
c. RE-clone the cloned backup BACK TO the internal drive
All done in a few clicks of the mouse (and the wait for the clone to re-copy back over).

Because you didn't do this, "getting back to where you once belonged" is going to be a lot more work... (sigh)

 

[hauntvictim]

So how does one go about, reverting to a lower OS? Is it as simple as downloading the previous OS if available from MAC app store then creating bootable drive on USB?

 

[Longkeg]

So how does one go about, reverting to a lower OS? Is it as simple as downloading the previous OS if available from MAC app store then creating bootable drive on USB?

Assuming there is no Time Machine backup available the only option to downgrade to an older MacOS is to completely erase the boot drive and do a clean installation of the desired OS. A newer OS (including it’s recovery partition) will usually not allow the installation of an older OS, a bootable installation drive may be the only way to do this.

 

[hauntvictim]

Interesting, and I have many Time Machine back ups. If I want to can I just select one with Yosemite and then all my current data just pick and choose from a current back up?

 

[Longkeg]

Interesting, and I have many Time Machine back ups. If I want to can I just select one with Yosemite and then all my current data just pick and choose from a current back up?

Maybe. You can certainly restore your machine to a point in time when it was running the desired (older) OS. What I'm not sure of is if you would then be able to restore files from a newer backup. Since at that point your Mac would be running an older OS with an older version of Time Machine. It's possible that the old version of Time Machine might not handle elements created with a newer version. I don't know this for a fact but you should be prepared for the possibility. You could try it and find out. If it doesn't work just install the latest OS and restore from your newest Time Machine backup to put everything back the way it was.

 

[hauntvictim]

Maybe. You can certainly restore your machine to a point in time when it was running the desired (older) OS. What I'm not sure of is if you would then be able to restore files from a newer backup. Since at that point your Mac would be running an older OS with an older version of Time Machine. It's possible that the old version of Time Machine might not handle elements created with a newer version. I don't know this for a fact but you should be prepared for the possibility. You could try it and find out. If it doesn't work just install the latest OS and restore from your newest Time Machine backup to put everything back the way it was.

That’s my fear. Also I have an old time machine that never backed up the latest OS, when I tried the other night... nothing. I do have current back up from a NAS.

 

[alvindarkness]

thanks! So yea, no time machine backup.

So I wipe and reinstall Yosemite (for example, if this is the version i want to revert back to)

I basically downgraded from High Sierra to Yosemite on an older 2011 MBP yesterday (for reasons that are difficult to explain, but completely related to the old AMDgate issue).

I thought I would try a radical approach, and basically deleted all folders apart from /Users and /Applications, then proceeded to install. I was surprised that there were only two niggles post install, one is that Mail didnt like the settings/preferences files from the newer version. The other is that imessages/facetime froze on start up. Both were easily fixed (just deleting a few iCloud preference and support files under ~/Library, and reimported the mail archives).

I also run a DAW on it occasionally and obviously had to reinstall all plugins as they are stored under /Library and not ~/Library, but everything is running smoothly.

Its not an approach I would recommend to most people, but just thought I'd throw it out there. In my case High Sierra was already on a HPFS volume and not APFS, so luckily I didnt have to futz about there - otherwise I wouldnt have bothered going as radical and woulve just restored from a backup (by hand) after downgrading.