Mojave External SSD not booting

[surfnode]

hello

I have just upgraded my parents 2014 Mac Mini from Sierra to Mojave. This installation is running from external SSD. The install completed however after booting up again the computer does not boot to SSD.

If I boot to old internal drive it cannot see the SSD partition and disk utility only sees an empty drive - is this maybe because APFS is not supported in Sierra? The SSD is not seen in boot menu when pressing alt at power-on. Does the internal old OS drive need to be updated to High Sierra at a minimum for the computer to support APFS - does it maybe install a firmware update to support APFS?

Thanks

 

[naerct]

Hi Surfnode, I don't know much about the Minis, but that's probably not the issue. You haven't given us much information. I am going to assume that you have USB3 ports on the Mini. Also, did you make certain that you did all the Sierra updates before trying to upgrade? So how is the SSD connected? Is it in an external enclosure, or do you have a USB to SATA cable so you don't need an enclosure. To boot, you need to be plugged directly into the Mac, not a hub. Some enclosures are not compatible as well (rare). I would try plugging it into another computer. Something may have happened during the upgrade, like the software not making the drive bootable. Not showing up in the startup disk list is a very bad sign. Was Sierra on the SSD before you tried to upgrade? I would check and correct the basics, but then try to do it again and watch carefully. It appears that you no longer have any OS on the SSD, so do you have a good version on the hard drive? I would never trust an upgrade without a backup. I always have clones from any OS boot disk. I usually just add a small partition to an external backup drive. Then I use Super Duper to make a clone of the drive I'm upgrading. The basic SuperDuper is free, but it's only $28 for all the extras which will save you a lot of time. CCC also works well too, but I think the fare is $50. So, somehow you want to do all the updates and then check again and do any more that show up. Then use SD and clone your current OS disk to an external. Then do the update on the clone, not the original. Also, the switch to APFS started with Sierra, but only for SSDs, and it's done automatically. I think in Mojave it does both. What I have discovered is that it is very difficult now to get an update to work. Apple requires no non-Metal video cards, and the use of APFS. However, I can say that Mojave will actually run on old, weak video cards on HSF+ formatted drives. So, make it easy for the upgrades, and then clone it to where you want it. One of my mistakes was that I didn't wait long enough for the unit to boot during installation, and had to start over. Good luck.
Neil

 

[LuisN]

hello

I have just upgraded my parents 2014 Mac Mini from Sierra to Mojave. This installation is running from external SSD. The install completed however after booting up again the computer does not boot to SSD.

If I boot to old internal drive it cannot see the SSD partition and disk utility only sees an empty drive - is this maybe because APFS is not supported in Sierra? The SSD is not seen in boot menu when pressing alt at power-on. Does the internal old OS drive need to be updated to High Sierra at a minimum for the computer to support APFS - does it maybe install a firmware update to support APFS?

Thanks

Update to high sierra first, I think your computer is missing an EFI update that brings APFS firmware support to your machine.

 

[naerct]

Hi Luis,
I thought about that because my cMPs need flashes with almost every point update since they are so old. That may well be the problem, and I usually recommend not skipping a version, but I helped someone recently and I tried to upgrade from 12 to 13, but the 14 installer came up, and worked just fine with the transition to Mojave, and still does, as I'm sure I'd know by now if it wasn't. I think the problem now is that the OP may have lost his Sierra configuration. With the cost of USB externals, it's unthinkable not to have at least one clone, so you don't have to start from scratch, and waste most of a day to put it back together and the loss of any data that wasn't backed up. SuperDuper is excellent for making boot clones and is free to use that basic feature. I've been using it for over 10 years. Upgrading is still only $28 (I think) which allows all the features, which includes a "Smart Update" which fractionalizes the time necessary to update a clone.
I hope Surfnode will give us some more details if he still has a problem. Here is a link from Apple that confirms you can upgrade directly from Sierra to Mojave on the Mac mini 2012 and later.
Neil