I have an encrypted APFS container with several volumes. The container lives on a physical partition (disk0s1), which is followed by more partitions (disk0s2, ...) with no free space in between. I need to expand one of the volumes on the container without having to move the other physical partitions in order to expand disk0s1. I know with LVM you can expand the container (physical volume) with other partitions which don't need to be adjacent, or even on the same hard drive. Is that possible with an APFS container?


There is no official documented way to add another physical storage to an existing APFS container.

I tried several possibly "undocumented" apfsVerbs like addPhysical, addPhysicalStorage or addStorage without success.

The feature may still be implemented later, since creating APFS FusionLCs is possible already:

diskutil ap createContainer [-main] device [-secondary] [device]


$ diskutil ap createContainer disk1s2 disk2s2    
Creating container with disk1s2 disk2s2
Started APFS operation on disk1s2 Data
Creating a new empty APFS Container
Unmounting Volumes
Switching disk1s2 to APFS
Switching disk2s2 to APFS
Creating APFS Container
FusionLC autodetect: LC Fusion
Created new APFS Container disk4
Disk from APFS operation: disk4
Finished APFS operation on disk1s2 Data

$ diskutil ap addVolume disk4 APFS Data
Exporting new unencrypted APFS Volume "Data" from APFS Container Reference disk4
Started APFS operation on disk4
Preparing to add APFS Volume to APFS Container disk4
Creating APFS Volume
Created new APFS Volume disk4s1
Mounting APFS Volume
Setting volume permissions
Disk from APFS operation: disk4s1
Finished APFS operation on disk4
  • 1
    Thanks for that, indeed it's strange that it seems possible to create a new container over two disks (but not more than two?) but not be able to add a disk to an existing container... – Aayla Secura Dec 21 '17 at 12:32
  • 1
    @AaylaSecura Apparently only two slices can be used to create a FusionLC - I tried it with three but got an error. – klanomath Dec 21 '17 at 12:47
  • This may be a bit late, but I don't think this is an answer to the OPs question. My understanding of fusion disks with APFS is for providing a large, slow hard-drive backing store for all the data and using a smaller, but much faster, SSD for the most commonly used data. The -secondary option above is not adding more storage, but a faster storage cache that stores copies of the most heavily used data. – penguin359 Jan 18 at 8:30

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