While the volumes stored in a APFS container are random access, the container itself is not. An APFS container is stored in a GPT partition. These types are partitions are sequentially stored on a drive. It is possible to expand a GPT partition to occupy space immediately before or after the partition. However, an APFS container can only be expanded to occur space immediately after, **but not before**. So you have two problems. First the ~400 GB of space is not immediately adjacent to the partition holding the APFS container. The partition with identifier `disk0s3` is between this space and the partition holding the APFS container. Second, the space is above the APFS container. So even if you were to remove `disk0s3`, you still could not add the space to the APFS container. To summarize: - While the drive and APFS allow random access, the GPT scheme does not. - APFS can be only be expanded downwards or shrunk upwards. If you wish to wipe the entire drive and create 1.4 TB APFS container followed by JHFS+ partition, then enter the following command. diskutil partitiondisk disk0 2 gpt apfs MyAPFS 1400G jhfs+ MyJHFS+ R The EFI partition will be created automatically. If the above command was executed on a 2 TB drive, then result would be the partitioning shown below. /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *2.0 TB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_APFS Container disk1 1.4 TB disk0s2 3: Apple_HFS MyJHFS+ 599.7 GB disk0s3 /dev/disk1 (synthesized): #: TYPE NAME SIZE IDENTIFIER 0: APFS Container Scheme - +1.4 TB disk1 Physical Store disk0s2 1: APFS Volume MyAPFS 24.6 KB disk1s1 The command `diskutil listfilesystems` produces the output shown below. From this output, one can determine that the `jhfs+` used in the above command means `Mac OS Extended (Journaled)`. Marlin:~ davidanderson$ diskutil listfilesystems Formattable file systems These file system personalities can be used for erasing and partitioning. When specifying a personality as a parameter to a verb, case is not considered. Certain common aliases (also case-insensitive) are listed below as well. ------------------------------------------------------------------------------- PERSONALITY USER VISIBLE NAME ------------------------------------------------------------------------------- APFS APFS (or) APFSI Case-sensitive APFS APFS (Case-sensitive) ExFAT ExFAT Free Space Free Space (or) FREE MS-DOS MS-DOS (FAT) MS-DOS FAT12 MS-DOS (FAT12) MS-DOS FAT16 MS-DOS (FAT16) MS-DOS FAT32 MS-DOS (FAT32) (or) FAT32 HFS+ Mac OS Extended Case-sensitive HFS+ Mac OS Extended (Case-sensitive) (or) HFSX Case-sensitive Journaled HFS+ Mac OS Extended (Case-sensitive, Journaled) (or) JHFSX Journaled HFS+ Mac OS Extended (Journaled) (or) JHFS+ Marlin:~ davidanderson$