Partition problem with APFS containers in macOS High Sierra

As always I'm so impatient and migrating with my main devices to the first developer previews the day they are available.

Which as always bring me only problems but I just cannot help myself.

So this time I wanted to see High Sierra before going all in. So I made a second partition and installed High Sierra in there. However after roughly 10 minutes I felt like I need to update my main partition anyway.

So I did. But now there is the catch. I have 2 partitions and I'm not able to merge them. And in an attempt to fix this situation I converted the second APFS container back to HFS+ and actually split it into two and converted only one back to APFS.

So now I have two APFS containers and one HFS+. Any ideas how to get this back to one and only APFS?

diskutil list:

  /dev/disk0 (internal):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                         251.0 GB   disk0
   1:                        EFI EFI                     314.6 MB   disk0s1
   2:                 Apple_APFS Container disk2         211.3 GB   disk0s2
   3:                  Apple_HFS Untitled                5.7 GB     disk0s3
   4:                 Apple_Boot                         134.2 MB   disk0s4
   5:                 Apple_APFS Container disk1         32.8 GB    disk0s5
   6:       Apple_KernelCoreDump                         655.4 MB   disk0s6

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +32.8 GB    disk1
                                 Physical Store disk0s5
   1:                APFS Volume Untitled                962.6 KB   disk1s1

/dev/disk2 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +211.3 GB   disk2
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            167.8 GB   disk2s1
   2:                APFS Volume Preboot                 29.3 MB    disk2s2
   3:                APFS Volume Recovery                521.1 MB   disk2s3
   4:                APFS Volume VM                      1.1 GB     disk2s4

diskutil apfs list:

APFS Containers (2 found)
|
+-- Container disk1 B254A72D-19C5-4D2C-B461-3C23F298E454
|   ====================================================
|   APFS Container Reference:     disk1
|   Capacity Ceiling (Size):      32750391296 B (32.8 GB)
|   Capacity In Use By Volumes:   78757888 B (78.8 MB) (0.2% used)
|   Capacity Available:           32671633408 B (32.7 GB) (99.8% free)
|   |
|   +-< Physical Store disk0s5 7F1CDC13-0E37-44CC-B96C-45EF55BA8410
|   |   -----------------------------------------------------------
|   |   APFS Physical Store Disk:   disk0s5
|   |   Size:                       32750391296 B (32.8 GB)
|   |
|   +-> Volume disk1s1 BDE7AAD6-A3D1-3561-B5C0-39FA6C46CCB1
|       ---------------------------------------------------
|       APFS Volume Disk (Role):   disk1s1 (No specific role)
|       Name:                      Untitled
|       Mount Point:               /Volumes/Untitled 1
|       Capacity Consumed:         962560 B (962.6 KB)
|       Capacity Reserve:          None
|       Capacity Quota:            None
|       Encrypted:                 No
|
+-- Container disk2 70F0772D-B309-405E-9ABE-6D99097B7E16
    ====================================================
    APFS Container Reference:     disk2
    Capacity Ceiling (Size):      211335577600 B (211.3 GB)
    Capacity In Use By Volumes:   169482776576 B (169.5 GB) (80.2% used)
    Capacity Available:           41852801024 B (41.9 GB) (19.8% free)
    |
    +-< Physical Store disk0s2 BDFDDFAF-CC5C-4ACC-9127-A5A5A33FF4CD
    |   -----------------------------------------------------------
    |   APFS Physical Store Disk:   disk0s2
    |   Size:                       211335577600 B (211.3 GB)
    |
    +-> Volume disk2s1 179EB384-BAEF-3A8D-8190-4EBE624E6DF9
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk2s1 (No specific role)
    |   Name:                      Macintosh HD
    |   Mount Point:               /
    |   Capacity Consumed:         167724068864 B (167.7 GB)
    |   Capacity Reserve:          None
    |   Capacity Quota:            None
    |   Encrypted:                 Yes (Unlocked)
    |
    +-> Volume disk2s2 128F2113-D584-4534-B5FC-81330EA8510A
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk2s2 (Preboot)
    |   Name:                      Preboot
    |   Mount Point:               Not Mounted
    |   Capacity Consumed:         29270016 B (29.3 MB)
    |   Capacity Reserve:          None
    |   Capacity Quota:            None
    |   Encrypted:                 No
    |
    +-> Volume disk2s3 092D2B6E-5DF9-4333-8B77-117E4A9994B0
    |   ---------------------------------------------------
    |   APFS Volume Disk (Role):   disk2s3 (Recovery)
    |   Name:                      Recovery
    |   Mount Point:               /Volumes/Recovery
    |   Capacity Consumed:         521072640 B (521.1 MB)
    |   Capacity Reserve:          None
    |   Capacity Quota:            None
    |   Encrypted:                 No
    |
    +-> Volume disk2s4 932E7677-4A65-4D9F-9C0D-F5C890E0BD13
        ---------------------------------------------------
        APFS Volume Disk (Role):   disk2s4 (VM)
        Name:                      VM
        Mount Point:               /private/var/vm
        Capacity Consumed:         1073766400 B (1.1 GB)
        Capacity Reserve:          None
        Capacity Quota:            None
        Encrypted:                 No

I would really appreciate any help.

Solution 1:

Well for anyone interested in a solution, it's now possible.

I've followed this guide and managed to reclaim all available space and resize my main partition back to full disk space.

Thanks everyone for help and suggestions.