Is there a way for my Sierra drive and see the Mojave?

machenryr

macrumors 6502
Original poster
Jan 25, 2016
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I upgraded to Mojave on a 5,1 MacPro. Yay for me. I'm trying to let go of my Sierra boot drive, but I can't just yet, not until I transfer everything and work out the kinks. Somethings I won't be able to, so I had been planning to keep the Sierra on an external boot. All of my drive bays and the optical bay is replaced with SSD. The Mojave Boot is on a PCIe SSD. But I have put the Sierra HD back in bay one so it can boot. It won't boot on an external enclosure.

BUT Sierra doesn't recognize the Mojave drive. Is there a way to do this? Is there an app for that? I have to boot to a High Sierra drive and THEN the Mojave SSD can be seen. Going from Mojave to the Sierra drive is easy. Going from Sierra back to Mojave is a two-step process.
 

LuisN

macrumors regular
Mar 30, 2013
199
184
Torres Vedras, Portugal
I upgraded to Mojave on a 5,1 MacPro. Yay for me. I'm trying to let go of my Sierra boot drive, but I can't just yet, not until I transfer everything and work out the kinks. Somethings I won't be able to, so I had been planning to keep the Sierra on an external boot. All of my drive bays and the optical bay is replaced with SSD. The Mojave Boot is on a PCIe SSD. But I have put the Sierra HD back in bay one so it can boot. It won't boot on an external enclosure.

BUT Sierra doesn't recognize the Mojave drive. Is there a way to do this? Is there an app for that? I have to boot to a High Sierra drive and THEN the Mojave SSD can be seen. Going from Mojave to the Sierra drive is easy. Going from Sierra back to Mojave is a two-step process.
Sierra does't read Mojave but Mojave reads Sierra.
Boot from Mojave and use migration assistant. Select only what you want to transfer to Mojave.
 
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machenryr

macrumors 6502
Original poster
Jan 25, 2016
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Sierra does't read Mojave but Mojave reads Sierra.
Boot from Mojave and use migration assistant. Select only what you want to transfer to Mojave.
Thank you. I understand that. I want to know if there's a way to boot or see Mojave from Sierra. It's a two-step process that's kind of a waste of time.
 

mikzn

macrumors 65816
Sep 2, 2013
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Vancouver
It's probably because Mojave is on APFS and Sierra is the old file system format HFS+

easiest thing to do is what LuisN recommended - use migration assistant - but you might have to upgrade some software to owrk properly on Mojave / APFS
 

machenryr

macrumors 6502
Original poster
Jan 25, 2016
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I have this installed but have yet to try it with an APFS drive. It is no longer supported.
https://www.paragon-software.com/us/business/apfs-kit-mac/
It's probably because Mojave is on APFS and Sierra is the old file system format HFS+

easiest thing to do is what LuisN recommended - use migration assistant - but you might have to upgrade some software to owrk properly on Mojave / APFS
I've already migrated most of my apps and docs. I'm splitting docs/movies/music into various other disks. I need to use this as a boot drive for other purposes. I'm not concerned with migrating data to the new SSD. I've done clean installs anyway. No, I need to be able to go from Sierra to Mojave.

I hope someone else has done an APFS Retrokit kind of thing.
 

mikzn

macrumors 65816
Sep 2, 2013
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Vancouver
you could upgrade the other drive to Mojave and they would both be on APFS - do you have any software that won't work on Mojave / APFS ?
 

machenryr

macrumors 6502
Original poster
Jan 25, 2016
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you could upgrade the other drive to Mojave and they would both be on APFS - do you have any software that won't work on Mojave / APFS ?
Funny, but I hadn't considered that. In large part because I wanted a fallback. So far it's been important. Certain programs like FCP couldn't be fully upgraded to the Mojave version, I was able to find and rectify on the APFS drive. Saved the day.