This volume is not formatted as APFS

You may be able to boot into Recovery Mode and convert the volume to APFS.

https://www.macworld.com/article/3230150/macos-high-sierra-startup-ssd-volume-must-be-apfs-other-drives-can-wait.html

You should make sure to have good verified working backups before attempting the procedure. If something goes wrong you will most likely need to erase the drive and either perform a clean reinstall of macOS or a restore from a backup.

See if you can convert the file system to APFS on the fly.

https://discussions.apple.com/thread/250713725?answerId=251390345022#251390345022

You should definitely make sure you have good verified working backups first in case something goes wrong. Also make sure you can either boot into Internet Recovery Mode (Command + Option + R) or boot a macOS USB installer in case you can no longer boot to the internal drive.

True. I've got 2 identical MacBooks Pro, both with MacOS Mojave, one has APFS, the other one Mac OS Extended (Journaled) file system...

If I wanted compatibility problems, system crashes and other impediments, I would use Windows :)

Please Apple, come up with a solution to this issue, as I don't want to get back to "know all about computers and software" state. For many years I've been comfortable with "it's so easy, I don't have to do anything" state and I'd like to keep it that way.

Why do you think this sneer is necessary to find a solution? I seem to have the same problem yet I always ran the upgrades the way apple provided them. I am running Mojave 10.14.4 at the moment and if you were right I should not have this problem. On top of that if automatic conversion was possible in Mojave, why not do it in Catalina as well?

nullibist wrote:

So i have an iMac with an internal 5400rpm IDE drive, formatted MacOS Journaled extended, which has Mojave 10.14 and i tried to install Catalina last night and got the message that the drive is not APFS so i can't install.

From what i've read, Mojave should already be APFS but there are some circumstances where you can end up with Mojave journaled extended instead. Is there a way to convert to APFS *without* wiping the drive, or do i have to do the Recovery Mode, use Disk Utility to erase and format the drive as APFS (is there a guarantee that APFS will not be greyed out in Disk Utility?), then choose the Install new MacOS. And at that point, which version of MacOS will it choose to install? Does it just download it from Apple and install it? I assume that it would get the latest version which would be Catalina.

It's all a bit confusing, so i'm going to hold off for a while until i get some answers.

Thanks.

Danny in Sydney.

Whatever you end up doing, make sure you have good verified working backups in case something goes wrong.

You could try booting into local Recovery Mode (Command + R) to try reinstalling macOS Mojave over top of itself to see if it will convert your drive to APFS. If it doesn't convert the drive, then you can try converting the drive to APFS using Disk Utility while booted into Internet Recovery Mode (Command + Option + R) or from a bootable macOS USB installer. If the Disk Utility GUI doesn't allow it, you can try using the command line version of "diskutil" to try converting the volume to APFS on the fly.

Worst case scenario you have to boot the Catalina installer (either from a bootable USB or from Internet Recovery Mode using Command + Option + R) to erase the physical drive and perform a clean install of Catalina.

bj3john4 wrote:

After several hours of Apple Support Chat two days ago, one of the support reps finally told me that the reason I couldn't reformat my drive (Samsung 860 EVO 1 TB) to APFS was because it wasn't a Macintosh drive.

All OEMs will blame third party hardware when things don't work correctly. I do know that some Samsung SSDs have had compatibility issues with Macs, but I don't know which ones. I wouldn't expect it to have a problem erasing the drive though, but APFS is a new file system so it is hard to say if Apple could be blocking some SSDs from using it.

AFAIK the only compatibility issue with third party SSDs is on systems using Apple's proprietary PCIe SSD connector. On these systems the macOS installer is unable to install the required system firmware if a non-Apple third party PCIe SSD is installed.

When I tried erasing the Samsung drive to reformat as APFS, there was no option to select APFS... and the reason I've been given is that it isn't a Macintosh drive.

Did you try erasing the whole physical drive? In order to see the physical drive in Disk Utility you need to click on "View" and select "Show all devices". You should then be able to select the physical drive in the left pane of Disk Utility to erase the drive as GUID partition and APFS (top option).

Maybe your system firmware was never fully updated so macOS is blocking you from using APFS.

Sometimes macOS has issues dealing with a drive if something unexpected occurs. When this happens I will erase the beginning part of the drive with zeroes to overwrite the partition table so the drive appears completely blank. If this doesn't work, then I will perform a hardware secure erase on the SSD which resets the SSD to factory defaults including erasing/blanking the SSD. To access the SSD's hardware secure erase feature requires using Linux. Parted Magic is a customized Linux boot disk with a customized app/script which makes it easy to perform the hardware secure erase.

Create a bootable Parted Magic USB drive using Etcher. Option Boot the Parted Magic drive and select the orange icon labeled "EFI". On the Parted Magic desktop there should be an icon for erasing drives. Within the app you need to select the "ATA Secure Erase" option. The "slow" erase option will not reset the SSD and will just cause undue wear and may make the problem worse. The "ATA Secure Erase" option will ask you to supply a password, so just type any simple word. The erase usually only takes 30seconds to several minutes to complete. You can get the last free version of Parted Magic from the MajorGeek's mirror link here.

Well, I finally got to my goal: upgrading Mojave running on Mac OS Extended (journaled) to Catalina running on APFS.

1. I found some advice suggesting that the FS conversion could be done in place: https://www.macobserver.com/tips/how-to/upgrade-mac-apfs-after-high-sierra/ When I tried it, the option in Disk Utility was grayed out (and I did select the proper boot volume).
2. I reformatted my internal SSD to APFS using Disk Utility.
3. Using Disk Utility, I attempted to restore the backup image I made using SuperDuper to the newly-formatted internal APFS SSD. Disk Utility errored out, saying that the volume in the image (which was not APFS) could not be restored to an APFS volume.
4. I used SuperDuper to successfully restore my backup to the internal SSD APFS volume.
5. I then upgraded from Mojave to Catalina using Software Update, with no problems.

What I did, that worked, for my situation:

1. Did the FS conversion, in place, as noted in the link in Randy N.'s post above
2. Exited Disk utility
3. Clicked on Install MacOs, in Recovery Mode, and let it reinstall Mojave. The Mojave install left everything in place (user accounts, applications, etc.). All this did was reinstall the OS and install the boot files; and, set up the disk to boot.
4. Rebooted the system and everything was working fine.
5. Then performed the update to Catalina.

My OS is on an external, USB attached SSD disk. The internal disk was available to boot, in Recovery Mode, to, in order to use Disk Utility. Because it is very difficult to replace an iMac disk, I went with the USB SSD disk. It is much faster than the stock 5400 RPM SATA drive.

This upgrade was performed on an IMac 21.5" mid 2015 system which has a maximum of 8GB memory. The SSD drive was a way to deliver high speed, without having to buy a new iMac, or having to pay to get an SSD installed. It turns out, for the Catalina update, it was good I had the internal disk to do this.

I have Time Machine running, and it was up to date, so I could recover if the OS reinstall wiped everything out.

It took under an hour to reinstall Mojave and upgrade to Catalina.

Everything seemed to work, as expected. I did not have any 32 bit apps, except Acrobat Reader, which I removed before I did the Catalina upgrade.

I hope people find this useful. Also, this may not work for everyone.

After a several hours of trial and error, and piecing together everyone's suggestion, here's what worked for me without having to reformat/erase drive.

My setup:

• iMac with Internal Samsung SSD (named My SSD)
• Mojave OS
• Format: Mac OS Extended (Journaled)
• Scheme: GUID Partition Map

1. Downloaded Catalina
2. Restart in Internet Recovery Mode (Command+Option+R after restart)
3. macOS Utilities -> Disk Utility
4. Select "My SSD" volume and Unmount
5. Edit -> Convert to APFS
6. Quit Disk Utility
7. macOS Utilities -> Reinstall macOS
8. Install macOS Catalina

Hope that helps.

@jayhawkfan88's solution worked for me, however there was one extra step that took me a bit to figure out (see step 4/5 below).

Note: I no longer have the original on board Drive, I upgraded it about a year ago to a 500GB SSD, which is how I am guessing I got into this predicament. This solution still worked for me even though I have a non OEM Drive.

Edit of jayhawkfan88's solution that worked for me below:

1. Downloaded Catalina
2. Restart in Internet Recovery Mode (Command+Option+R after restart)
3. macOS Utilities -> Disk Utility
4. Select "My SSD" volume and Unmount (My drive was already unmounted, and the Convert to APFS in step 6 was greyed out).
5. If your drive is already unmounted and you cannot select Convert to APFS in step 6, mount the drive first, you will be asked for your password to unlock the drive. Then unmount it. The Convert to APFS option will then be available (after the drive has been unlocked and unmounted).
6. Edit -> Convert to APFS
7. Quit Disk Utility
8. macOS Utilities -> Reinstall macOS
9. Install macOS Catalina

I don't think there is a quick solution. How I did it after trying all proposed ' fixes':

1. Made a full backup with rsync
2. Reboot with cmd-R and formatted my drive with the Disk Utility to APFS (complete wipe)
3. Installed macOS (Mojave) and booted normally
4. Restored everything with rsync
5. Upgraded to Catalina...

Downside of this method ...It took a few hours. But other than that it went flawlessly and everything works smoothly.

I did something similar:

• Full backup with Time Machine to external SSD
• Reboot with cmd-R and formatted with Disk Utility to APFS (complete wipe)
• Installed Mojave while using recovery mode tool
• Booted to default Mojave
• Migrated everything from backup to Mojave with Migration Assistant.
• Installed Catalina update.

My first attempt: backup, cmd-R recovery, re-partition/format to APFS, restore from backup with recovery mode, didn't work since the recovery mode restore formats that drive back to the incorrect partition type.

This worked:

• Full backup with Time Machine
• Reboot with cmd-R and formatted with Disk Utility to APFS (complete wipe)
• Installed Mojave while using recovery mode tool
• Booted to default "blank" Mojave
• Migrated everything from backup to Mojave with Migration Assistant.
• Installed Catalina update.

Well, Randy_N, at least I can tell you what NOT to do. I'm just finishing restoring my MacBook from a backup (I use TimeMachine with WDMyCloud) because I followed what was meant to be "a safe option" to convert into APFS. I run my computer in Recovery Mode, unmounted primary drive, converted the filesystem into APFS and it worked. The filesystem is now APFS but I had to either reinstall the system or restore it from backup, which I did. After almost 4h my computer will be like new :)