Downgrade Mac Os High Sierra?

sbkevinmichael

macrumors member
Original poster
Sep 4, 2017
95
40
Anaheim, CA
Is it possible to downgrade? It's not compatiable with sling tv that i use to airplay to my apple tv 3!

I have a 2013 27 inch imac and how do i do it?
 

Fishrrman

macrumors P6
Feb 20, 2009
17,182
5,536
OP:

What kind of backup do you have?
Answer that question first -- then we can advise on how to proceed...
 

Septercius

macrumors member
Oct 5, 2017
35
52
UK
I've successfully downgraded my 2017 iMac and MacBook 12" to macOS Sierra (the version they were originally supplied with).

1. Backup everything you need to.
2. Reboot holding down Cmd+Option+Shift+R to enter Internet Recovery mode.
3. Wait for it to download the installer. This should be the original version that was installed on your computer (Sierra in my case).
4. Once the installer starts, open up the Terminal via the menu and delete any APFS volumes and containers using "diskutil". This will replace the APFS partition (if you have one) with a nice HFS+ one.
5. Quit Terminal and reinstall in the usual way. It was quick on my iMac, but the MB took a while.

My main reason for downgrading was issues with Spotlight, which basically made it useless.
 
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Mlrollin91

macrumors G5
Nov 20, 2008
13,477
8,687
Ventura County
The OP cannot use recovery mode to restore Sierra as it’s not a machine that shipped with Sierra. It’s from 2013 so it probably shipped with Mavericks.
 

Princess Cake

macrumors 6502
Jan 15, 2010
299
203
Cheboygan, MI
High Sierra's been officially released right? Because this feels like we're beta testing...... I haven't been this annoyed with a version of OSX since Lion b0rked my perfectly well-oiled Snow Leopard.... jeez I wish I had that OS back.
 
Last edited:

Fishrrman

macrumors P6
Feb 20, 2009
17,182
5,536
I'll try to help.

The OP has learned a hard lesson.
He didn't backup.
Now he can't "get back to where he once belonged".
Not without a lot of trouble, anyway.

OP: here's what you need to do.
You must read and follow ALL of these instructions.

First, you need to create a backup of your internal drive (to preserve your account, apps, and data).

You'll need an external hard drive (can be USB, platter-based drive, SSD, anything).

You'll need to download CarbonCopyCloner (or SuperDuper). Either is FREE to download and use for 30 days.

Get the above.
Then connect the external drive.
Run CCC and create a cloned backup of what you have now.
Make it an "HFS" backup (so you can mount it on older versions of the OS)
Then let CCC "do its thing".
Set this backup aside for the moment.

Next:
You'll need a USB flashdrive 16gb or greater.
Initialize it to HFS+ with journaling enabled
You'll need one of the following (all are free to download):
- Boot Buddy
- Install Disk Creator
- DiskMaker X
You'll need a copy of the Low Sierra installer

Use one of the apps above to create a BOOTABLE version of the Low Sierra installer on the USB flashdrive.

NEXT:
DO NOT DO THIS UNLESS YOU HAVE BACKED UP AS ABOVE!
Boot from the bootable USB installer.
Go to Disk Utility
ERASE your internal hard drive -- set it HFS+ with journaling enabled

Now the internal drive is reinitialized to HFS with nothing on it, ready to install a brand-new copy of the OS.

Install Low Sierra onto the internal drive.
When done, it will reboot into the new install.
Begin the setup.
At the appropriate moment, setup assistant will ask if you wish to migrate stuff from the old Mac or drive.
Connect the bootable backup you made earlier and "aim" setup assistant at it.
See if you can set it up to migrate apps, accounts and data.
WARNING: this may or may not work, because you're trying to migrate from a volume "newer than" Low Sierra.
If this doesn't work, DON'T DESPAIR. There are other methods around this.

See if the migration will "go through".
If it does, good.
If it doesn't, ignore the external drive.
Set up a "basic account" but DO NOT use the username and password that you normally use, instead use something like "temp" (this will be fixed later).

Then, get back to us.

You've got some work to do, son, if you want to "get back"...
 

gawalla

macrumors newbie
Feb 13, 2016
4
0
I'll try to help.

The OP has learned a hard lesson.
He didn't backup.
Now he can't "get back to where he once belonged".
Not without a lot of trouble, anyway.

OP: here's what you need to do.
You must read and follow ALL of these instructions.

First, you need to create a backup of your internal drive (to preserve your account, apps, and data).

You'll need an external hard drive (can be USB, platter-based drive, SSD, anything).

You'll need to download CarbonCopyCloner (or SuperDuper). Either is FREE to download and use for 30 days.

Get the above.
Then connect the external drive.
Run CCC and create a cloned backup of what you have now.
Make it an "HFS" backup (so you can mount it on older versions of the OS)
Then let CCC "do its thing".
Set this backup aside for the moment.

Next:
You'll need a USB flashdrive 16gb or greater.
Initialize it to HFS+ with journaling enabled
You'll need one of the following (all are free to download):
- Boot Buddy
- Install Disk Creator
- DiskMaker X
You'll need a copy of the Low Sierra installer

Use one of the apps above to create a BOOTABLE version of the Low Sierra installer on the USB flashdrive.

NEXT:
DO NOT DO THIS UNLESS YOU HAVE BACKED UP AS ABOVE!
Boot from the bootable USB installer.
Go to Disk Utility
ERASE your internal hard drive -- set it HFS+ with journaling enabled

Now the internal drive is reinitialized to HFS with nothing on it, ready to install a brand-new copy of the OS.

Install Low Sierra onto the internal drive.
When done, it will reboot into the new install.
Begin the setup.
At the appropriate moment, setup assistant will ask if you wish to migrate stuff from the old Mac or drive.
Connect the bootable backup you made earlier and "aim" setup assistant at it.
See if you can set it up to migrate apps, accounts and data.
WARNING: this may or may not work, because you're trying to migrate from a volume "newer than" Low Sierra.
If this doesn't work, DON'T DESPAIR. There are other methods around this.

See if the migration will "go through".
If it does, good.
If it doesn't, ignore the external drive.
Set up a "basic account" but DO NOT use the username and password that you normally use, instead use something like "temp" (this will be fixed later).

Then, get back to us.

You've got some work to do, son, if you want to "get back"...
@Fishrrman I am in the exact same situation as the OP. I have been working tirelessly to figure this out (I had taken similar, but not exact steps as you mentioned above - instead I had backed up the High Sierra version of my MBP's SSD to Time Machine as instructed on another website - so I might go back and do your version anyway, but I digress.)

In any case, just as I was about to reformat my internal SSD, I realized that I cannot format my SSD as HFS+ anymore - only the APFS options are available.

Is there another step in there to get back to HFS+ for the older versions? I am beyond frustrated right now as the only reason I'm downgrading is because High Sierra "broke" my 2nd external monitor connection on DisplayLink.

OR ... can I possibly just restore the Time Machine HS backup to my MacBook Air (which I was switching to anyway, longer story) which is still running Sierra?

Thanks much in advance for the use of your brains ...
 

davidlv

macrumors 65816
Apr 5, 2009
1,240
20
Kyoto, Japan
@Fishrrman I am in the exact same situation as the OP. I have been working tirelessly to figure this out (I had taken similar, but not exact steps as you mentioned above - instead I had backed up the High Sierra version of my MBP's SSD to Time Machine as instructed on another website - so I might go back and do your version anyway, but I digress.)

In any case, just as I was about to reformat my internal SSD, I realized that I cannot format my SSD as HFS+ anymore - only the APFS options are available.

Is there another step in there to get back to HFS+ for the older versions? I am beyond frustrated right now as the only reason I'm downgrading is because High Sierra "broke" my 2nd external monitor connection on DisplayLink.

OR ... can I possibly just restore the Time Machine HS backup to my MacBook Air (which I was switching to anyway, longer story) which is still running Sierra?

Thanks much in advance for the use of your brains ...
It is possible to install using the older file formay. See the complex instructions below, which you may have to edit to fit your usage case.
"
Install HighSierra without converting to APFS

Make sure the installer file is in the /Applications folder, run the command below from the terminal.

/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --converttoapfs NO


/Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall --applicationpath /Applications/Install\ macOS\ High\ Sierra.app --agreetolicense --converttoapfs NO --nointeraction

Note: When you enter your password in Terminal, no text will be displayed, giving the impression that Terminal isn’t accepting your input. This is a security feature to ensure prying eyes can’t see your password as it is typed.

You’ll be presented with the license for using macOS High Sierra. You can agree to the license terms by entering a capital A at the prompt.

The startosinstall script will start copying needed files to the target disk (in this example, the current startup disk). You’ll see Terminal counting up to one hundred. When it reaches 100, all the needed files will have been copied, and your Mac will reboot and start the actual installation of the new operating system without converting the startup disk to APFS.

To specify what drive to install macOS High Sierra on, other than the startup drive, you need to add the following to either of the Terminal command lines listed above:

— volume /path to the volume you wish to use

An example for installing macOS High Sierra on a drive named HighSierra without converting the target volume to APFS would be:

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall –applicationpath /Applications/Install\ macOS\ High\ Sierra.app –converttoapfs NO –volume /Volumes/HighSierra


This would force the installation to occur on a volume named HighSierra. An easy way to enter the actual pathname to the drive you wish to use is to enter the command in Terminal without the actual pathname, so the command would end after — volume (make sure there’s a space after the word volume). Now drag the drive from the Finder and drop it on the Terminal window. Terminal will add the actual pathname to the drive for you. All that’s left to do is press enter or return.

The — volume switch will also work when you wish to force a conversion to APFS, as shown in this example, which will convert the drive named HighSierra to APFS and install the new version of macOS:

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/startosinstall –applicationpath /Applications/Install\ macOS\ High\ Sierra.app –converttoapfs YES –volume /Volumes/HighSierra

By using the startosinstall command from within Terminal, the choice to convert to APFS or leave the target drive’s format unchanged is entirely up to you."
Good luck. I was successful doing this on a SSD in a Mac Pro.
Works fine and diskWarrior can still be used.
 

gawalla

macrumors newbie
Feb 13, 2016
4
0
See this article for reversion to HFS+ https://www.techrepublic.com/article/how-to-revert-back-to-apples-hfs-from-apfs/ Note that the text typed in the article is incorrect for the command, the screenshot of terminal is accurate.
Thank you for this. I am getting an error that says the "volume OWC 1.0TB couldn't be unmounted because it is in use by process 0 (kernel)"

I never made any partitions on the drive (I'm no techie, indeed) - is that the problem here? I'm really out over my skis on this from a knowledge standpoint so your assistance is much appreciated.
 

hallux

macrumors 68030
Apr 25, 2012
2,774
485
Thank you for this. I am getting an error that says the "volume OWC 1.0TB couldn't be unmounted because it is in use by process 0 (kernel)"

I never made any partitions on the drive (I'm no techie, indeed) - is that the problem here? I'm really out over my skis on this from a knowledge standpoint so your assistance is much appreciated.
You'll need to boot to Internet Recovery or from a flash drive built for MacOS installation.
 

gawalla

macrumors newbie
Feb 13, 2016
4
0
I've successfully downgraded my 2017 iMac and MacBook 12" to macOS Sierra (the version they were originally supplied with).

1. Backup everything you need to.
2. Reboot holding down Cmd+Option+Shift+R to enter Internet Recovery mode.
3. Wait for it to download the installer. This should be the original version that was installed on your computer (Sierra in my case).
4. Once the installer starts, open up the Terminal via the menu and delete any APFS volumes and containers using "diskutil". This will replace the APFS partition (if you have one) with a nice HFS+ one.
5. Quit Terminal and reinstall in the usual way. It was quick on my iMac, but the MB took a while.

My main reason for downgrading was issues with Spotlight, which basically made it useless.
For some reason when I enter Internet Recovery my only option is to re-install High Sierra with APFS formatting.
 

mikzn

macrumors 65816
Sep 2, 2013
1,432
705
Vancouver
Very old post. Apple didn’t offer a link back in October.
it got resurrected - lol

That being said, i've always been able to find an official OSX download link on apple support pages, and have always used that to install a fresh OSX install or combo upgrade from a bootable drive rather than using internet recovery or creating a flash drive. I find it quicker and easier ( as long as you have a bootable drive handy)