Lost space after a failed windows10 installation

The external installation will do several things.

• It is the equivalent of the macOS 'Live CD'.
• Allow you to boot from a disk, which has the correctly-sized local Recovery HD
• Your internal disk can be unmounted, when you boot from the external disk
• Your internal disk can be repaired, when you boot from the external disk, including re-installing macOS on the internal disk, without touching non-macOS files.
• If we erase the 230GB Recovery HD, we have a proper Recovery HD on the external disk.

You can also achieve the same thing by downloading macOS High Sierra from the App store and How to create a bootable installer for macOS - Apple Support to boot from it. Be aware that the bootable installer does not have a local Recovery HD.

Apple has an article How to fix a split Fusion Drive - Apple Support. I prefer to run the commands by hand to ensure there are no issues.

Once in Terminal, we need to erase both internal physical disks. Booting in Recovery can renumber disks, so we need to be careful on the next steps. If you run diskutil list, you will see two internal drives. One is your 120GB SSD part, the second is your 2TB HDD part. I will call the SSD as disk0, and HDD as disk1. If they are different, adjust the steps accordingly.

Steps should be

• Erase the SSD - diskutil eraseDisk jhfs+ SSD disk0
• Erase the HDD - diskutil eraseDisk jhfs+ HDD disk1
• Create the Fusion (CS) Volume Group - diskutil cs create macOS-LVG disk0s2 disk1s2 (please ensure the SSD is first).
• The previous step will output a long string similar to, which I will use as an example.

  F5D64E6C-7796-48E9-955E-46429D58A9BF

• Create the Fusion (CS) Volume - diskutil cs createVolume F5D64E6C-7796-48E9-955E-46429D58A9BF "Macintosh HD" 100% . The "100%" allocates the entire capacity of the two combined drives to "Macintosh HD".
• Post the output of diskutil cs list, before we start the restore.

Give the current state, you do not know where the real Recovery partitions ends, even though you know where it starts. How will GParted let you determine the end? You will need to guess. I do not recommend it.

If you are feeling adventurous on your corporate Mac, try the steps I recommended. The GParted method can cause worse problems.

mikelis wrote:

Thanks for Your help, but sorry, this didn't fix nothing at all

here's what I did:

booted into recovery hd (cmd+R)

selected reinstall macOS

it takes hella time to install and then brings me back to my desktop with everything already restored

FD reports being 1.8tb

System partition still at 1,17tb

Did you choose an external disk to re-install macOS? The default is the internal disk, which will not correct anything.

mikelis wrote:

is there anything else I can do?

You need to install macOS on an external disk, which has nothing else on it.

• It should not be the Time Machine disk on which you made a backup.
• It should not be the Internal disk.

mikelis wrote:

3: Apple_Boot Recovery HD 231.2 GB disk1s3

This is a known bug in High Sierra. It does not correctly merge the disk space back into the main Fusion drive, leaving it instead merged into the Recovery HD. The Recovery HD should be only ~650MB, but this is 231GB. The safest solution in this case is a TM backup/erase/rebuild Fusion drive/restore.

The other option is to use Local Recovery, if it works, install macOS on an external disk, erase Recovery HD on the internal disk, and re-install macOS from the external disk, which will again create the correct size Recovery HD, leaving Free Space at the end. The Free Space can be converted to a FAT partition which BCA should merge, but it can again cause the same issue, which becomes an infinite loop case.

mikelis wrote:

It wont work if I just back up my data and then do a fresh install trough the command+r recovery menu, then restore?

Command+R used the Recovery HD, which is now 230GB. Please try to boot into Local Recovery HD and test if it works properly? If Command+R works, you cannot erase the partition that you are using to run Recovery Console. 😉

mikelis wrote:

Since I don't have a backup drive and I'm kinda willing to risk it, maybe You happen to know how I could resize these partitions in terminal?

You can convert the large Recovery HD to free space, and run Disk Utility to try and merge the space, but merging HFS into a CS LV is not supported. You will need to erase underlying disks, not partitions.

mikelis wrote:

D/L'ing High Sierra image to create the 'LiveCD' I hope this finally does it.

If you follow instructions. 😉. Since you have a Time Machine backup of macOS, there is no longer any need to install macOS on the external disk.

You originally had

No, I don't even have a spare 1tb drive right now

then

I accidentally wiped one of my drives, so now I have a backup drive.

There are two different methods, depending on the first state or the second state being the current state.

Before we go further, can you post the output of

diskutil list

diskutil cs list

Since you have an external TM disk now, there is no need to install macOS. Once we know the current state, we can decide what are the next steps. Again, do not wipe the TM disk, keep your backup or create one now.