| 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. |
