Mm 1,1-6,2 Recognising a container disk volume

[marclondon]

With some spare time I've been resurrecting a 2012 i7 Mini which had a faulty SSD. I had upgraded it with the now faulty SSD and retained the 1TB hard disk.

I have taken out the bad SSD and found a decent one from a faulty MacBook Pro that runs the Mini very well. I have stripped the Mini right down as the faulty SSD was in the top position, and moved the HDD to the top slot and put the working SSD where the HDD was.

But booting from the SSD I can only see one partition of two on the HDD - half of it (the bootable volume; the other is called backup and mounts fine) just isn't mounting and on disk utility is showing as unnamed.

Booting from the HDD shows the system is in a container disk. The system on the HDD is Mojave, and the system on the good SSD is El Capitan.

I'm thinking this is a file system issue - will putting a newer system (eg Mojave) on the SSD solve this?

 

[Fishrrman]

It looks like the HDD is formatted for APFS (Mojave).

The SSD with El Cap will be formatted HFS+ (Mac OS extended, journaling enabled, GUID partition format).

El Cap does not "understand" APFS formatting.
Hence, the missing partition.

Upgrade the Mini SSD to Mojave, and everything should be recognized.

TIP:
If you're having trouble obtaining a copy of Mojave, you can use dosdude1's "Mojave patcher" to get it.
You don't actually "patch" anything.
All you do is go to the "tools" menu, and there's an option to download Mojave.

macOS Mojave Patcher

Then, create a bootable flash drive.
I suggest using the free "Install Disk Creator" to do this:

Make a Bootable USB macOS Installer Download the update for Big Sur compatibility -

What’s needed for a clean install on a Mac A backup of the disk before it’s erased. Two options are to use Duplicate (a free utility which can copy and paste an entire bootable volume), or Mac Backup Guru (a paid, fully featured backup utility with unique incremental backups capability) for...

macdaddy.io

 

[marclondon]

It looks like the HDD is formatted for APFS (Mojave).

The SSD with El Cap will be formatted HFS+ (Mac OS extended, journaling enabled, GUID partition format).

El Cap does not "understand" APFS formatting.
Hence, the missing partition.

Upgrade the Mini SSD to Mojave, and everything should be recognized.

Thanks - what I thought. But I'm puzzled as to why one partition on the HDD is readable - are there different file systems on the two partitions?