Dual boot on Fusion Drive on 2017 iMac

Question

Level 1

8 points

Dual boot on Fusion Drive on 2017 iMac

Hi,

I have a 2017 iMac on which I have restored the Fusion Drive. However, I have some older software (Apple Aperture for example) and Hardware - a Canon Scanner - so I have starting installing Mojave (and using the disk utility that came with it) and created another partition to install Ventura. I have tried different ways to create a patrician and container, but the system slows down and the Ventura install stops with 12 minutes to go according to the update - all it seems to have done is copy the install files - taking several hours - to the new partition. I have waisted considerable time without getting anywhere.

My only options is to split the Fusion Drive and then create 1 tb partitions on the main drive. I had previously successfully used a similar setup using the 128gb SSD for the operating system and the programme files, but the photo software required too much disk space. This had also crawled to a complete stop and hence I started to recreate the fusion drive as described above...

(PS I still have a working M1 MacBook Pro and also an old MacBook Air that runs the older software.

Any help and suggestion would be appreciated.

(the options that is of course available is to install a large SSD which could solve all the problems but I am not confident in opening the iMac.

Thank you......Tom

iMac 27″ 5K, macOS 10.14

Posted on Jan 14, 2024 11:54 PM

Reply

Answer 1

Top-ranking reply

Servant of Cats

Level 8

43,123 points

Jan 15, 2024 4:26 AM in response to Tomsheck

There's another option: Get an external SSD, and install one (or both) operating systems on it.

This would avoid the risk of doing surgery on your Mac – and since your Mac has both USB-A (USB 3.0) and USB-C (Thunderbolt 3) ports, there is a wide range of SSDs to choose from. You can get preassembled 1 TB external SSDs for under $100. (Or go on Amazon and get an internal SSD and a matching USB, USB-C, or Thunderbolt enclosure.)

No need to have someone mess around inside of the iMac unless that Fusion Drive is actually throwing errors which will crash the machine regardless of which disk you're using as a startup disk.

Reply

Answer 2

Jan 16, 2024 3:26 AM in response to Tomsheck

Tomsheck wrote:

Thank you all for the replies. I have a 1 TB external SSD, which I could use. I assume this is similar to creating the install USB for Mojave Installer?

You probably wouldn't need to create a bootable USB installer – just to download an appropriate installer from the App Store links in

How to download and install macOS - Apple Support

and to run it against the desired volume on the external SSD. This assumes that you have a working Mac that can run the installer in question.

Given the reports of people erasing their Macs and then having trouble restoring them from Internet Recovery, it probably would be a good idea to have some sort of bootable recovery volume (clone backup, clean install, USB installer, etc.) on hand – rather than just erasing the internal drive first, then hoping for the best.

Reply

Answer 3

Barney-15E

Level 10

124,296 points

Jan 15, 2024 3:45 AM in response to Tomsheck

Stop trying to partition it and create a Volume on the drive.

A partition will exist on the mechanical HDD and be too slow to use. I don’t think that slowness would have caused the failed install, though.

Reply

Answer 4

Old Toad

Level 10

217,572 points

Jan 15, 2024 3:12 PM in response to Tomsheck

If your Canon scanner is your primary concern have you tried the demo version of VueScan. I've used it with an older Canon scanner very successfully.

Otherwise I'd go with Servant of Cats' suggestion and get an external SSD and install Monterey on it an run from it. I have the same year iMac and run Monterey on an external SSD in this inexpensive 1 TB configuration:

Reply

Answer 5

Jan 15, 2024 4:27 AM in response to Tomsheck

Use more than one version of macOS on a Mac - Apple Support

Reply

Answer 6

Tomsheck Author

Level 1

8 points

Jan 16, 2024 2:29 AM in response to Tomsheck

Thank you all for the replies. I have a 1 TB external SSD, which I could use. I assume this is similar to creating the install USB for Mojave Installer? I also have a mid 2011 MacBook Air running High Sierra to use with the scanner the scanner, as long as it will last, and to run Aperture on. I ahem just been slow in moving old photos to Lightroom or Capture One.

Or even a 2015 MacBook Pro but which also has some problems. I had to change the bulging battery to take it back to Britain. Now only runs with an external keyboard and track pad (I have changed the internal cable for the track pad already) but it runs.

However, the slowness of the drive suggest an issue with the Fusion Drive and I think I will have start from first principles.

Apple also has controls build into the operating system that may cause problems with creating an external drive to run Mojave on - but let me try if that applies to external hard drives. So I shall have to see what I can do and achieve

Thank you and regards,

Tom

Reply

Dual boot on Fusion Drive on 2017 iMac

Similar questions