Problem in upgrading from Mojave 10.14.6 to Catalina on 2015 Fusion drive iMac

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Level 1

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Problem in upgrading from Mojave 10.14.6 to Catalina on 2015 Fusion drive iMac

I recently tried to upgrade from Mojave to Catalina using the built-in updater. Toward the end of the update, the progress bar froze for a long time, then there was an error message saying there was a problem but didn't say why, then a circle with a strike out bar appeared and then the screen went black. I tried rebooting my iMac and the same thing happened ending with the circle with the strike out bar and black screen.

I had to go reboot the iMac with a backup hard drive and reinstall everything from my Time Machine backup disk. It is all back to normal now but I'm afraid to try and upgrading again to Catalina. What could be the problem?

My iMac is 2015 fusion drive with 32 GB RAM. Running 10.14.6 on it now but the internal hard disk is in the HFS file system. Would this have a bearing on the problem?

Thanks,

iMac Line (2012 and Later)

Posted on Mar 23, 2020 1:40 PM

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Answer 1

Kappy

Level 10

362,007 points

Mar 23, 2020 2:12 PM in response to VE3VLF

The HDD part of the Fusion Drive should be formatted HFS+, so that is normal and has no bearing on the problem. I'm uncertain as to whether you downloaded a full upgrade installer (about 5GBs) or if you downloaded an update installer (2-3GBs.) You cannot update Mojave to Catalina. You must upgrade Mojave. Please check this out to be sure you have the correct installer. What may have happened is that your old system was garbled by an installer problem to the point where the only option was to erase the disk and reinstall your backup.

You shouldn't fear updates or upgrades as long as you have backups, which you do. Under the worst of possible outcomes, you can recover from the backup. You did the right thing. This time around I suggest you verify that you have the correct installer, then proceed with the upgrade.

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Answer 2

Kappy

Level 10

362,007 points

Mar 23, 2020 3:06 PM in response to VE3VLF

Sorry, my error. Yes, the Catalina installer is about 8GBs. That is the upgrade installer. Might I suggest that before you run the upgrade, you do the following:

Repair the Drive for El Capitan or Later

Restart the computer. Immediately, at or before the chime, hold down the Command and R keys until the Apple logo and progress bar appear. Wait until the Utility Menu appears.
Select Disk Utility and press the Continue button.
Then select the indented (usually, Macintosh HD) volume entry from the side list.
Click on the First Aid button in the toolbar and wait for the Done button to activate. Click on it, then quit Disk Utility.
Select Restart from the Apple menu.
Immediately, at or before the chime, press and hold down the SHIFT key.
Release the key after the Apple logo and progress bar appear.
Safe mode startup is much slower than normal startup, so be patient.
When the Login Screen appears enter your admin password. If you use automatic login, then this means you are in safe mode.

Once in safe mode run the Catalina installer. I think this will help avoid installation problems.

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Answer 3

Kappy

Level 10

362,007 points

Mar 23, 2020 7:42 PM in response to VE3VLF

You cannot convert an HFS+ formatted drive to APFS if the former contains files. In this case, you need to reformat the entire drive. Before you do that you need to backup any files you don't want erased.

Installing Mojave does not require formatting the drive APFS but you will find that you must pay close attention at the start of the process in order to skip reformatting from HFS+ to APFS. However, this should not be a problem with a Fusion Drive because they need to be formatted HFS+ because APFS does not work well on HDD. It was developer specifically to run on SSDs.

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Answer 4

VE3VLF Author

Level 1

9 points

Mar 24, 2020 4:35 PM in response to Kappy

Hi Happy;

Thanks for the info but I came across a YouTube video that showed how to convert your internal HD to APFS even with files on the HD. Other sites had the same procedure but the video had one difference. In Disk Utility and in Recovery mode, you go to the View menu and check off Show all Devices. Then you highlight the Macintosh HD in the Disk Utility sidebar, then in the Edit menu you find Unmount and click on that. After that, go to the Edit menu and the Convert to APFS is now highlighted.

So far so good. I clicked it and Disk Utility converted the HD to APFS no problem. Just when I thought all was well, I rebooted the HD and then it went right back to the Recovery mode and I didn't press any keyboard buttons. I kept trying to reboot and the same thing kept happening. I went to select the HD under the startup command and I got an error message. It was not looking good!

So, I took my bootable backup drive to get into the iMac again and then I brought up Carbon Copy Cloner to restore the HD from the backup, just to see what would happen. It didn't take long as I did not erase the internal HD and it just replaced some files. It was late, so I left it and didn't bother to reboot the machine off its internal HD after the restore was done, as it was getting late.

I didn't think it would work but when I booted it up this morning, it worked! I got in fine and the internal HD is now in the APFS format with all my files! I don't know what happened during the restore but it fixed the problem, and without having to erase my internal HD. The bootable hard disk is still in HFS+ and I'll leave it that way for now.

Next step is to upgrade to Catalina but after all the stress from last night, I'm going to put that off for a few weeks until I get up the nerve again to try. At least the iMac is APFS converted and that's fine for now!

Thanks for your willingness to help. Much appreciated.

Cheers,

Ed

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Answer 5

VE3VLF Author

Level 1

9 points

Mar 23, 2020 2:43 PM in response to Kappy

Hi Kappy

I had downloaded it via the Software Update in the Systems Preferences panel. The size of it was 8 GB. Is this an upgrade installer? Given its size I assume so and that it is the correct one. I'll try it again this evening and see what happens. I still have my backups in case it goes crazy again. Hopefully what I experienced was a one time anomaly. I'll let you know how it went.

Thanks,

Ed

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Answer 6

VE3VLF Author

Level 1

9 points

Mar 23, 2020 5:37 PM in response to Kappy

Thanks for the suggestion. I did so and then I loaded the Catalina installer. As it was running, it asks where do you want to install it. However, the internal HD was greyed out with the note that it is not in the APFS format. So I cancelled it and now back to Mojave with HFS. Now I need to convert the HD from HFS to APFS. I tried that this afternoon with a few methods I found on line using Disk Utility while in Recovery mode. However, the convert to APFS command in the Edit menu of Disk Utility is greyed out. Not sure what to do now. Maybe I should reinstall Mojave? Will that convert the HD to APFS as well? May give it a try.

Ed

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Answer 7

VE3VLF Author

Level 1

9 points

Mar 23, 2020 6:15 PM in response to VE3VLF

The only other option I see is to complete erase the internal hard drive and reformat in APFS, which Disk Utility in the Recovery mode does provide that option, i.e. it is not greyed out. But that of course means wiping all the data. Yes, I have a back up disk and Time Machine but can I do a full restore with the target disk now formatted as APFS while the source disk is HFS+?

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Problem in upgrading from Mojave 10.14.6 to Catalina on 2015 Fusion drive iMac

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