Can’t re-install MacOS - recovery mode showing two HDs?

mjodotcom wrote:

I have been trying to reinstall MacOS on my 2017 MBP using internet recovery but the installs have failed. I then went into the disk utility on recovery and saw that I seem to have two internal 500gb HDs listed when I really only have one. An attempt to erase the APFS drive goes fine (selected MacOS Extended, GUID map) but then if I do first aid it says it’s corrupted (exit code 8) and to run first aid in recovery mode - which I already am…I also can’t erase the bottom “top level” HD, with an error saying it couldn’t open the device.

I am wondering if this is all related to this weird HD split and how I can get things moving forward again?

https://discussions.apple.com/content/attachment/9891b839-7e58-4754-8306-8c2d9fd067c7

It says unformatted...?

GUID / APFS

if you want fresh install erase/format/initialize the parent drive:

is this the OEM SSD that shipped new with the Mac or you replaced it at some point with a third party?

mjodotcom wrote:

Any sense for why recovery disk utility is showing these two drives and why I can’t get an install to stick? Seems like it’s related to this behavior and the fact that doing a first aid on the top drive fails even when in recovery

https://discussions.apple.com/content/attachment/689d3980-775d-4e92-98b6-6cb4b2108797

You can try reseating the PCIe SSD

or

You can try replacing the drive if it has failed an un-repairable.

OWC/Macsales has excellent customer support for compatible drives and /or enclosures for replacements if applicable for exact 2017:

MacBook Pro SSD (Solid-State Drive) Upgrades - OWC

I’m wondering if you do not have a split Fusion Drive (as you mentioned). Have you looked at this article: How to fix a split Fusion Drive - Apple Support?

The fact that the SSD and the other drive show similar sizes would preclude that but it’s worth taking a look at this article if you know for sure that you have a Fusion Drive.

mjodotcom wrote:

No worries. It is part of my confusion here - why does disk utility think I have two parent level drives, and why can’t I get MacOS installed on the one that can be found (bottom one can’t be found when I try to format it)

"using internet recovery but the installs have failed...."

If you are in 'Recovery' you can not erase/reformat/initilze the parent drive as new— to reinstall

is my only thought you have to be in 'Internet Recovery'

Bootable USB installers have a DiskUtility to do the same — if you have one available for your macOS

Create a bootable installer for macOS

mjodotcom wrote:

Maybe if you state what exact Mac this is... 2017(?)

The only place I ever saw a fusion drive was in a Desktop

diskutil list internal

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *121.3 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage Macintosh HD 121.0 GB disk0s2

3: Apple_Boot Boot OS X 134.2 MB disk0s3

/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_CoreStorage Macintosh HD 998.7 GB disk1s2

3: Apple_Boot Recovery HD 650.0 MB disk1s3

/dev/disk2 (internal, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Macintosh HD +1.1 TB disk2

Logical Volume on disk0s2, disk1s2

C5D87019-7A9D-44EA-9C63-D8873D11B135

Unencrypted Fusion Drive

mjodotcom wrote:

Sorry, I said 2017 MBP for in the OP for “MacBook Pro”

I should of looked myself...

That was what I had original thought , until some suggestion of Fusion drive was introduced.