How to delete APFS volume when there's no visible APFS container..?

[stephengrenfell]

I have an mid 2011 iMac SSD boot disk (SSD 240GB) running HS 10.13.6 that's got itself into a twist.

iMac wouldn't boot - it stops at end of progress bar and stays there. Machine would only boot if the internal SSD was disconnected.

I put the SSD into a USB caddy on my mac mini - and see the problem.

There is no APFS container, just the APFS volume.

- the APFS container is not visibe in Disk Utility or listed with diskutil list in Terminal
- Disk Utility says the APFS volume still exists but cannot be mounted or deleted
- Erasing in Disk Utility creates another Apples HFS partition leaving the unmounted AFPS volume still there

diskutil apfs deleteContainer

Doesn't work on a disk.

See attached images

Anyone help solve this, please.

Thanks.

[Edit : I just realised this is the wrong thread - should be in macos High Sierra, sorry.]

 

[chrfr]

What's the output of

diskutil apfs list

 

[stephengrenfell]

What's the output of

diskutil apfs list

Thanks for replying @chrfr

But in the meantime, I used Erase in Disk Utility to create another Apples HFS partition and then put the SSD back into the iMac. This allowed to start up from an external HS 10.13.6 installation disk. And then I re-installed HS 10.13.6 + recover user data from time machine backup. All seems to be back to normal now.