How to remove APFS container to regain space?

[Ben J.]

Hi.
Imac 2017, 10.15.6, internal hybrid 1tb HD, 2x fast SSDs on TB, slow SSD on USB for backup.

I've succesfully been running the system on a fast SSD via thunderbolt, and using the internal drive for storage (HFS+) plus a APFS partition w/CarbonCopyCloner clone of the boot disk. Now I have a new disk for the boot clone and I want to free up space on the internal drive by deleting the APSF partition. Turns out not to be so easy.

What info I've found online is that it has to be done via terminal. Also, when it concerns the internal drive, that it must be done when booted from recovery partition.

I guess my main question is; must it be done from recovery partition when it's not my boot volume, just because it's the internal SATA?

And any advice appreciated. I barely know how to copy/paste commands in Terminal.

 

[Taz Mangus]

Since you are not booted to your internal drive, you don't need to boot to Recovery Mode. If your internal boot clone has been moved to another external drive, then it sounds like the internal drive is free to be simply erased, or is that not the case?

 

[Ben J.]

Since you are not booted to your internal drive, you don't need to boot to Recovery Mode. If your internal boot clone has been moved to another external drive, then it sounds like the internal drive is free to be simply erased, or is that not the case?

Thanks, Taz.
No, my internal 1tb now has the 200gb apfs container (emptied) and a pretty full 800gb hfs+ partition.
I guess I could copy all the files to another drive, format the whole drive, and copy the files back, and that would solve it. I thought I could just delete the apfs container and regain the space.

Another thing; from what I read, it's adviced to keep spinners on hfs+, and that's what I was planning to do. Do you think it makes a difference? It's painfully slow compared to my external SSDs.

 

[Taz Mangus]

Thanks, Taz.
No, my internal 1tb now has the 200gb apfs container (emptied) and a pretty full 800gb hfs+ partition.
I guess I could copy all the files to another drive, format the whole drive, and copy the files back, and that would solve it. I thought I could just delete the apfs container and regain the space.

You could just use this command from Terminal:

diskutil eraseDisk JHFS+ <Disk Name> /dev/<APFS device>

Getting the <APFS device> is pretty easy with:

diskutil list

Another thing; from what I read, it's adviced to keep spinners on hfs+, and that's what I was planning to do. Do you think it makes a difference? It's painfully slow compared to my external SSDs.

APFS is really ideal for SSD drives.

 

[Ben J.]

That's great info, thanks.
I've just started CCC cloning of the 800gbs, and when that's finished, I'll try to get rid of the container with your fine recommendations. I'd like to try it out, just to get more familiarized with how APFS works. Anyway I'm backed up.
I'll report back.

 

[Ben J.]

Success.

I didn't succeed at first, got errors in terminal, and I think it had to do with names/identifiers and such.
I picked up some info here:

macOS Sierra: Delete Your APFS Partition the Right Way

When it's time to delete your APFS partition, there's a right and a wrong way. Let's look at how to do it right.

www.macobserver.com

…and with the command:
diskutil apfs deleteContainer disk0s0
(with the right "disk..."-name, not the zeroes here)
... the apfs container now showed up in DU as a regular HFS+ partition.
I could then delete it, and the 200gbs were released, and I have one single 1tb hfs+ volume!

Thanks, Taz.
And perhaps this might be of help to others also.

(Added: keep in mind, anyone, this cannot be used on the drive you're booting from. You'll then have to do it in recovery mode)