diskutil
program is a native Apple command line utility for manipulating disks, partitions, and RAID sets. This includes magnetic hard disks, CDs/DVDs, and flash drives. Most options, except "list", require root access.Finding out about disks in your system
For information on all available disks and their partitioning, use:diskutil list
For more detailed information on a particular disk or partition, use:diskutil info disk-or-partition
The default Apple partitioning scheme uses the last physical partition on a disk for storing data. Here is sample output from diskutil list
showing a hard disk and a CD. The UNIX device name is shown first, along with the contents of each partition:
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *74.5 Gi disk0
1: Apple_partition_map 31.5 Ki disk0s1
2: Apple_HFS Macintosh HD 74.4 Gi disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: CD_partition_scheme *718.1 Mi disk1
1: Apple_partition_scheme 625.3 Mi disk1s1
2: Apple_partition_map 31.5 Ki disk1s1s1
3: Apple_HFS Dungeon Siege Disc 2 625.0 Mi disk1s1s2
Here is sample output from diskutil info
on a disk partition:
diskutil info /dev/disk0s3
Device Identifier: disk0s3
Device Node: /dev/disk0s3
Part Of Whole: disk0
Device / Media Name: Untitled 3
Volume Name: Macintosh HD
Mount Point: /
File System: Journaled HFS+
Journal size 8192 KB at offset 0x256000
Owners: Enabled
Partition Type: Apple_HFS
Bootable: Is bootable
Media Type: Generic
Protocol: ATA
SMART Status: Verified
Volume UUID: EE8C4FFD-6C4B-302D-B096-DCF81D4E13FB
Total Size: 74.4 Gi (79892103168 B) (156039264 512-byte blocks)
Free Space: 26.8 Gi (28731383808 B) (56115984 512-byte blocks)
Read Only: No
Ejectable: No
Whole: No
Internal: Yes
Checking partitions for integrity and fixing them
You can use diskutil
to check the file system data structure of a partition (e.g., /dev/disk0s3) with:diskutil verifyVolume partition
If errors are you found, you can fix them with:diskutil repairVolume partition
Checking partitions for UNIX permission problems and repairing them
You can use diskutil
to check the UNIX permissions on a partition with:diskutil verifyPermissions partition
If errors are you found, you can fix them with:diskutil repairPermissions partition
If permissions get accidentally changed on some system files, it could cause strange behavior or disable certain features of the system.
Finding out about RAID sets
RAID is usually used in servers to provide additional protection from hard disk failure. For information on RAID sets, use:diskutil listRAID
Other diskutil options
In addition to the options listed above, diskutil
can be used to reformat disks or partitions, erase writable CDs/DVDs, securely erase data, etc. Here are some of the other features:
- u[n]mount - Unmount a single volume
- unmountDisk - Unmount an entire disk (all volumes)
- eject - Eject a removable disk
- mount - Mount a single volume
- mountDisk - Mount an entire disk (all mountable volumes)
- eraseDisk - Erase an existing disk, removing all volumes
- eraseVolume - Erase an existing volume
- reformat - Reformat an existing volume
- eraseOptical - Erase an optical media (CD/RW, DVD/RW, etc.)
- zeroDisk - Erase a disk, writing zeros to the media
- randomDisk - Erase a disk, writing random data to the media
- secureErase - Securely erase a disk or freespace on a volume
- resizeVolume - Resize a volume, increasing or decreasing its size
See the man page for even more!