Disk has 944 GB free, but Boot Camp says "The startup disk does not have enough space to be partitioned"

it was, since the original fusion drive was an apple blade ssd + mechanical hard disk, and this one is the apple blade ssd + sandisk ssd. was there a way to designate the blade ssd as the main drive? the instructions I followed didn't mention this. I don't mind remaking the fusion drive and reinstalling, if I can fix this issue in the process. thanks for your help!

edit: I think I found the solution? I looked up a different set of instructions and in it they specify that the faster drive (the blade ssd) must be listed first when creating the fusion drive. I have no idea which I typed in first so this may have caused the issue.

yep, this was exactly the issue. i originally made the fusion drive based on pre-apfs instructions, using the old JHFS+ system, then reformatted to APFS to install mojave. this time i followed APFS instructions and it turned out perfect. boot camp is working without a hitch. thanks again!!

diskutil list:

/dev/disk0 (internal):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                         28.0 GB    disk0

   1:                        EFI EFI                     314.6 MB   disk0s1

   2:                 Apple_APFS Container disk2         27.7 GB    disk0s2

/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_APFS Container disk2         1000.0 GB  disk1s2

/dev/disk2 (synthesized):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      APFS Container Scheme -                      +1.0 TB     disk2

                                 Physical Stores disk0s2, disk1s2

   1:                APFS Volume Macintosh HD            122.3 GB   disk2s1

   2:                APFS Volume Preboot                 45.0 MB    disk2s2

   3:                APFS Volume Recovery                512.4 MB   disk2s3

   4:                APFS Volume VM                      3.2 GB     disk2s4

diskutil apfs list:

APFS Container (1 found)

|

+-- Container disk2 2C98A754-DBBB-4C99-8F88-DEB2B873AF39

    ====================================================

    APFS Container Reference:     disk2 (Fusion)

    Size (Capacity Ceiling):      1027680514048 B (1.0 TB)

    Capacity In Use By Volumes:   134868496384 B (134.9 GB) (13.1% used)

    Capacity Not Allocated:       892812017664 B (892.8 GB) (86.9% free)

    |

    +-< Physical Store disk0s2 056DD564-ECC4-44BB-A470-3D8A80CE4312

    |   -----------------------------------------------------------

    |   APFS Physical Store Disk:   disk0s2 (Secondary, Designated Aux Use)

    |   Size:                       27685384192 B (27.7 GB)

    |

    +-< Physical Store disk1s2 154D2300-D67A-4E79-9BB0-A08F76F7F09C

    |   -----------------------------------------------------------

    |   APFS Physical Store Disk:   disk1s2 (Main)

    |   Size:                       999995129856 B (1000.0 GB)

    |

    +-> Volume disk2s1 74FCFDD6-8FAC-41F6-B258-A1B7995E602B

    |   ---------------------------------------------------

    |   APFS Volume Disk (Role):   disk2s1 (No specific role)

    |   Name:                      Macintosh HD (Case-insensitive)

    |   Mount Point:               /

    |   Capacity Consumed:         122277588992 B (122.3 GB)

    |   FileVault:                 No

    |

    +-> Volume disk2s2 379A46C3-A401-4FAE-AAA0-E33BCBB8B455

    |   ---------------------------------------------------

    |   APFS Volume Disk (Role):   disk2s2 (Preboot)

    |   Name:                      Preboot (Case-insensitive)

    |   Mount Point:               Not Mounted

    |   Capacity Consumed:         44998656 B (45.0 MB)

    |   FileVault:                 No

    |

    +-> Volume disk2s3 1B3A2556-F0B9-44D4-A230-C8EE4A3B8AB0

    |   ---------------------------------------------------

    |   APFS Volume Disk (Role):   disk2s3 (Recovery)

    |   Name:                      Recovery (Case-insensitive)

    |   Mount Point:               Not Mounted

    |   Capacity Consumed:         512385024 B (512.4 MB)

    |   FileVault:                 No

    |

    +-> Volume disk2s4 ED73A4E1-4A90-4359-833B-343D50984F1E

        ---------------------------------------------------

        APFS Volume Disk (Role):   disk2s4 (VM)

        Name:                      VM (Case-insensitive)

        Mount Point:               /private/var/vm

        Capacity Consumed:         3221245952 B (3.2 GB)

        FileVault:                 No