High Sierra to Sierra

Peter Franks

macrumors 68000
Original poster
Jun 9, 2011
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Hi. Can someone tell me how I can get back to Sierra.

Had I switched back from my CCC straight away it would’ve been fine. However... I’ve waited 3/4 months. So my work docs, downloads and offline emails have accumulated and I need them for reference in my old Sierra.

I have a copy of my Sierra SSD as it was 4 months ago. As the system is now APFS are all the docs etc still compatible if I make a Time Machine of the High Sierra. Can I pick and choose what I want to put back onto the old Sierra if I put that SSD back in and will it read APFS emails/docs/files, or does it make no difference.

I hope this makes some sense to someone. Alternatively if TM is not the answer can someone please tell me how else I can do this idiot proof-wise.

Thanks.....
 

Fishrrman

macrumors Core
Feb 20, 2009
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First, what kind of Mac?
MacBook Pro?
Does it have an easily removable hard drive? (i.e., non-retina)

The "copy of your Sierra SSD". Was that created by CCC or Time Machine?
IF it's a CCC cloned and bootable backup, you're in luck. TM, and things are gonna be harder.

Don't be concerned about the "4 months ago" part.
That can be handled later.

Fastest, easiest way (with a bootable cloned backup):
1. Make a bootable clone of the High Sierra install onto a backup drive (DO NOT use the drive that has Low Sierra on it !!!!!!)
2. Boot from the Low Sierra drive
3. ERASE the internal drive to Mac OS extended with journaling enabled
4. Use CCC to "re-clone" the Low Sierra drive BACK TO the internal drive. Get the Mac "back up and running" using Low Sierra. This is the important thing!
5. Now, mount the backup of the High Sierra drive, and "manually move over" all the "newer stuff" (files created since 4 months ago).
 
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Peter Franks

macrumors 68000
Original poster
Jun 9, 2011
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Thanks Fish. Re 1) I just have the SSD with HS in the MBP, and one with Low S which I cloned before upgrade.
Would it be easier to just put back the CCC clone of Sierra into the MBP, yeh it is pre retina.

How do I move over the newer stuff. I know when I try to boot from the SSD externally it's painfully slow. How do I see the internal and external SSD, I thought I could only do one or the other. How can I see the external to pick stuff from
 

Fishrrman

macrumors Core
Feb 20, 2009
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"Would it be easier to just put back the CCC clone of Sierra into the MBP, yeh it is pre retina."

YES. If you have the tools, do it that way. Should only take about 15 minutes.

"How do I move over the newer stuff."

1. First, put the old drive back into the MBP, so you can boot and run from Low Sierra.
2. Get booted into Low Sierra
3. Connect the drive with High Sierra on it, let it mount on the desktop
4. Click ONE TIME on the drive icon to select it
5. Type "command-i" (eye) to bring up the get info box
6. At the bottom of get info, click the lock and enter your password
7. In "sharing and permissions", put a CHECKMARK into "ignore ownership on this volume"
8. Close get info

You can now open the High Sierra drive "in the finder", and "manually move" the newer files you want to bring over to the older installation.
You won't have "permissions problems" because of the get info trick we just did above.

Be aware that if you were using a newer version of the apps that created the files on the High Sierra drive, they might not open (using older versions of the same app) on the Low Sierra drive.
But don't worry about this beforehand.
 
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Peter Franks

macrumors 68000
Original poster
Jun 9, 2011
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That's brilliant help, thanks. I've always wondered how I could link up a bootable SSD and dip into it without it booting. I didn't know you could do that. So how will it appear, all as files and folders, and 'on my mac' emails are all on there?

Not sure I understand the command/eye bit, for get info. Is it not like other drives where the right click brings up the get info? where do I type that, and what's the eye in brackets mean? Do I type all of that

Thank you!
 
Last edited:

Fishrrman

macrumors Core
Feb 20, 2009
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"Not sure I understand the command/eye bit, for get info"

Don't overthink this.
Just follow the instructions I gave, step by step.
 

Peter Franks

macrumors 68000
Original poster
Jun 9, 2011
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I don’t actually understand this line

Type "command-i" (eye)

I write that with the brackets and inverted commas? Is that what you mean
 

Longkeg

macrumors 6502
Jul 18, 2014
393
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S. Florida
Literally, on your computer keyboard, press The command key and the letter I key at the same time. This is the keyboard shortcut for Finder-> File-> Get Info. “Get Info” is the Apple equivalent of “Properties” in Windows. Not sure why he writes (eye)... it doesn’t matter.
 
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Peter Franks

macrumors 68000
Original poster
Jun 9, 2011
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Can anyone tell me where I'd find the Mail Folders, the ones that are 'On My Mac' to move from High Sierra to Sierra. Not the 'Inbox' folders. Either from the drive or from a TM back up, if that would work? Thanks
 

Fishrrman

macrumors Core
Feb 20, 2009
19,084
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I have no idea where they would be in Time Machine, I've never once used it.

IF you have a cloned backup drive, I would look in:
home/library/Mail

Try this using Mail.app:
1. File-->import mailboxes
2. Choose "import data from" "files in mbox format"
3. You will now see a dialog box in which you can navigate to home/library/mail
4. Go there and see if Mail will "bring these in".
5. If it does, you will have a new mailbox that I believe is called "imported" or something like that
6. It's now up to you to either leave it "as imported" or move things around into existing mailboxes or create new mailboxes for them.
 
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