diskutil

Utility to manage local disks and volumes. More information: https://ss64.com/osx/diskutil.html.

List all currently available disks, partitions and mounted volumes:

diskutil list

Repair the filesystem data structures of a volume:

diskutil repairVolume {{/dev/diskX}}

Unmount a volume:

diskutil unmountDisk {{/dev/diskX}}

Eject a CD/DVD (unmount first):

diskutil eject {{/dev/disk1}}