Cannot upgrade to Catalina as HD is not APFS. Any ideas on how to fix it?

Rogjack wrote:

I tried to erase my HD with disk utility option but I could not as option is grayed out. I read online it is not recommended, any ideas how to fix it?

I don't think I said that, just reported my experience with updating to Catalina where the installer automatically converted the file system to APFS.

Is that a problem?

I am trying to sift through your issue and how to resolve that issue—

From your original question: If you are going to reformat the drive—you can not be booted to the drive.

From "Internet Recovery">DiskUtility>View>Show All Devices> here you have to select the physical drive erase/format/partition that drive.

 Recovery: https://support.apple.com/en-us/HT204904

Alternative you can use the Disk Utility from a bootable USB installer, a bootable Time Machine backup.

Reboot holding the option key to mount one of these alternative drives to carry on.

I installed from software update to Catalina. The Mac rebooted and downloaded and installed Catalina from the Internet, it was not booted from the Mac.

When I reinstalled Mojave I had to create a bootable USB stick with the Mojave installed to restore it.

The point was that updating from Mojave to Catalina did not require booting from an external drive, the install process converted the drive to ABFS.

The OP wanted to install Catalina and could not format the drive, I just pointed out it wasn't necessary.

I installed Catalina on an HFS formatted fusion drive and it was converted to APFS by the install process.

Since then I have reverted to Mojave though the file system remained APFS. This has not caused any problems.

During the release of Mojave Apple chose not to format fusion drives APFS due to problems that were encountered, since then they must have resolved those problems.

Rogjack wrote:

I installed Catalina on an HFS formatted fusion drive and it was converted to APFS by the install process.

Since then I have reverted to Mojave though the file system remained APFS. This has not caused any problems.

During the release of Mojave Apple chose not to format fusion drives APFS due to problems that were encountered, since then they must have resolved those problems.

So are you saying the issue is solved?

Maybe the parent (physical) drive GUID partition table stays

Restart the Mac into Recovery Mode.

Launch Disk utility.

Click-select your named boot volume. (Not the physical drive above it.)

In the Disk Utility Edit menu, select Convert to APFS

Rogjack wrote:.

The OP wanted to install Catalina and could not format the drive, I just pointed out it wasn't necessary.

rogelio1550

Rogjack

I lost track of the OP and your subsequent post, I try to restrict my feed back to the OP only—and there has been no reply.

I don't think I said that, just reported my experience with updating to Catalina where the installer automatically converted the file system to APFS.

Is that a problem?

You can can convert HFS to APFS from Recovery. https://support.apple.com/en-us/HT204904

from the Disk Utility>View>Show All Devices> ( parent drive )> Edit>Convert to APFS

No data lose. It is surprisingly fast conversion.

Non-Destructive APFS Conversion

Apple provides non-destructive methods for start-up disk drives for APFS conversion, and hence no data (files or folders) will be lost.

On the other hand, APFS formatting will erase all the files and folders stored on the external hard drive.

Always advised to have a current backup plan in place, especially upgrades, updates, file conversion— in this way you can fall back with no lose of data if something goes wrong.

"3-2-1 backup strategy" for more info. How to create a boot clone