diskutil

Utility to manage local disks and volumes

List all currently available disks, partitions and mounted volumes.

diskutil list

Repair permissions on a volume

diskutil repairPermissions {{/Volumes/Name}}

Repair the file system 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}}