Although the functions of Apple's Disk Utility application aren't a traditional part of the Unix command-line environment at least not in a single application Apple has provided an interface to most Disk Utility functions through the diskutil program.
 Table 10.26. The Command Documentation Table for diskutil
diskutil  | Modify, verify and repair local disks  | 
diskutil <verb> [<options>]  |   | 
Renames, ejects, mounts or unmounts disks and volumes.  | 
Verbs and Their Available Options  |   | 
list [device]  | Lists the disks currently known and available on the system, or on a specific device.  | 
info [device]  | Get disk information on all, or a specific device.  | 
Managing Disks  | 
unmount [force] <device>  | Unmounts a single disk partition (volume) (for example, diskutil unmount /Volumes/MyDisk or diskutil unmount disk2s1)  | 
unmountDisk [force] <device>  | Unmounts an entire drive, and all partitions/volumes on it (for example, diskutil unmountDisk force /dev/disk1)  | 
eject <device>  | Ejects a disk  | 
mount <device>  | Mounts a single volume/partition (for example, diskutil mount disk2s2). (Useful when a volume has been unmounted by hand, and you want it back!)  | 
mountDisk <device>  | Mount all volumes on a drive.  | 
Controlling Disk Parameters and State  | 
rename <device> <newname>  | Renames volume. Renames the volume specified as the first argument. For example, diskutil rename /dev/disk1s2 Spanky or diskutil rename /Volumes/MyDisk /Volumes/YourDisk.  | 
reformat <device>  | Reformats the <device> in the existing format.  | 
randomDisk [times] <device>  | Writes random data to <device>, optionally do it [times] times. Useful for wiping sensitive data that you don't want the black-helicopter crowd sniffing from your disk surface.  | 
secureErase [level] <device>  | Erase a disk using even more paranoia than randomDisk. Levels 1, 2, and 3 specify one-pass random data, US DoD 7-Pass secure erase mode, and Guttman algorithm 35-pass secure erase mode. Even the black helicopter crowd doesn't know how to get around this one.  | 
enableJournal <device>  | Enable HFS+ journaling on the <device>  | 
Checking and Repairing Disks  | 
verifyVolume <device>  | Verifies the structure of a volume.  | 
repairVolume <device>  | Repairs the structure of a volume.  | 
repairPermissions <device>  | Repairs the permissions of an Mac OS X boot volume. Some people report constant, inexplicable problems with their disk permissions going awry, but we've never seen this happen on our machines.  | 
RAID Tools  | 
CreateRAID mirror|stripe <name> <format> <device> <device> [<device> ...]  | 
Creates a RAID set on multiple disks or volumes. Format can be HFS, HFS+, JournaledHFS+, UFS, MS-DOS. We've seen situations where creating a journaled RAID would not properly install the journal, and creating the RAID in HFS+ then enabling journaling separately was required.  | 
enableRAID mirror|concat  | Converts a single filesystem or volume into an unpaired mirror  | 
<device>  | RAID set (essentially a degraded mirrored RAID with no existing partner), or the beginning of a concatenated set.  | 
convertRAID <device>  | Converts a RAID converted on Panther or earlier, to Tiger's new 2.x RAID. Personally, we're skeptical that we have the intestinal fortitude to try this with our 2.5 TB XServe RAID!  | 
repairMirror <raidDisk> <newDisk>  | Repairs a failed mirror. <raidDisk> is the existing RAID, and <newDisk> is the replacement drive/volume to pair into the mirror. <raidDisk> and <newDisk> need to be a /dev/ nodes or disk identifiers.  | 
<device> in these commands can be named volumes, such as /Volume/MyStuff, device nodes such as /dev/disk1s3 (disk 1, partiton 3) or /dev/disk1 (all of disk 1), or just the disk-identifier portion out of the device node name (i.e. disk1s3 or disk1). Some of these don't make sense in certain contexts, such as using the reformat verb on a full drive with multiple partitions, or the mount verb on a named volume. Apple's documentation doesn't suggest what will happen if you use a peculiar combination, so avoid the ones that don't make sense.  |