home brew fusion/hybrid drives on OS X

There’s plenty of examples of doing this already but it’s as simple as:

$ diskUtil coreStorage create ssdDisk hddDisk
$ diskUtil coreStorage createVolume VolumeUUID jhfs+ "fusion Drive" 100%

Seems to be working so far, although with typical Apple there’s no documentation on how files/objects are moved between the SSD and HDD components