Disk Utility Tool (Mac OS X )

Most options require root access to the device diskutil <verb> <options>

list partitions information info eject mountDisk/unmountDisk all mountable volumes mount/umount verifyVolume repairVolume eraseVolume verifyPermissions repairPermissions repairOS9Permissions rename reformat resizeVolume partitionDisk removing all volumes eraseDisk eraseOptical zeroDisk randomDisk (writing random data to the media secureErase enableJournal/disableJournal HFS+ createRAID enableRAID Convert a disk to a degraded RAID mirror set convertRAID Convert a RAID 1.x pre-Tiger to a RAID 2.x Tiger updateRAID Update seiings addToRAID Add a spare or member disk removeFromRAID Remove a spare or member disk checkRAID repairMirror Repair damaged set destroyRAID diskutil verb with no options will provide help on that verb diskutil resizeVolume disk1s2 limits Volume format does not support resizing

Disk Utility Tool

Non-destructively resize a disk.

Only supported on GPT media with a Journaled HFS+ filesystem. When decreasing size, optionally supply a list of new partitions to create.
Ownership of the affected disk is required.
Valid partition sizes are in the format of .
Valid sizes are B(ytes), K(ilobytes), M(egabytes), G(igabytes), T(erabytes)

Example: 10G (10 gigabytes), 4.23T (4.23 terabytes), 5M (5 megabytes)

A size of limits displays the range of valid values for the current filesystem.
Example: diskutil resizeVolume disk1s3 10G JHFS+ HDX1 5G MS-DOS HDX2 5G

Valid filesystems:
HFS, HFS+
Case-sensitive HFS+
Journaled HFS+
Case-sensitive Journaled HFS+
MS-DOS, MS-DOS FAT12, MS-DOS FAT16, MS-DOS FAT32
UFS, Linux, Swap diskutil manipulates the volume-level structure of local disks. It provides information about, and allows the administration of, the partitioning scheme of disks, optical discs, and AppleRAID sets.

list [-plist | disk]	sudo diskutil list /dev/disk0 #: type name size identifier 0: Apple_partition_scheme *55.9 GB disk0 1: Apple_partition_map 31.5 KB disk0s1 2: Apple_HFS MacHD 14.2 GB disk0s3 3: Apple_HFS DATA 3.8 GB disk0s5 4: Apple_HFS PHOTOS 3.8 GB disk0s7 5: Apple_UNIX_SVR2 120.0 MB disk0s8 6: Apple_HFS BACKUPS 23.3 GB disk0s10 7: Apple_Boot 8.5 MB disk0s13 8: Apple_UNIX_SVR2 1015.5 MB disk0s14 /dev/disk1 (SD card from camera) #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *2.0 GB disk1 1: DOS_FAT_16 DGERMAN181 2.0 GB disk1s1 /dev/disk2 (unmounted! xxx.dmg ?) #: TYPE NAME SIZE IDENTIFIER 0: Apple_partition_scheme *1.5 MB disk2 1: Apple_partition_map 32.3 KB disk2s1 2: Apple_HFS Google Chrome 12.0.7... 1.5 MB disk2s2 sudo diskutil list -plist <?xml version="1.0" encoding="UTF-8"? <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd" <plist version="1.0" <dict <key>AllDisks</key <array <string>disk0</string <string>disk0s1</string <string>disk0s2</string <string>disk0s3</string <string>disk0s4</string <string>disk0s5</string <string>disk1</string <string>disk1s1</string <string>disk2</string <string>disk2s1</string <string>disk2s2</string </array <key>VolumesFromDisks</key> <array> <string>Macintosh HD</string> <string>DATA</string> <string>Photos</string> <string>HDIMAGES</string> <string>DGERMAN181</string> <string>Google Chrome 12.0.742.112-12.0.742.122 Update</string> </array> <key>WholeDisks</key> <array> <string>disk0</string> <string>disk1</string> <string>disk2</string> </array> </dict> </plist> See the DEVICES section below for the various forms that the device specification may take for this and all of the other diskutil verbs. The top-to-boiom appearance of partitions in diskutil list always indicates the on-disk ordering. BSD disk identifiers may, in certain circumstances, not appear in slice-numerical order when viewed this way. This is normal and is likely the result of a recent partition map editing operation in which volumes were kept mounted.
info MountPoint |      DiskIdentifier |      DeviceNode |      UUID information [-plist] …	† diskutil info /volumes/data Device Identifier: disk0s3 Device Node: /dev/disk0s3 Part of Whole: disk0 Device / Media Name: Untitled Volume Name: DATA Escaped with Unicode: DATA Mounted: Yes Mount Point: /Volumes/DATA Escaped with Unicode: /Volumes/DATA File System Personality: Journaled HFS+ Type (Bundle): hfs Name (User Visible): Mac OS Extended (Journaled) Journal: Journal size 8192 KB at offset 0xbd000 Owners: Enabled Partition Type: Apple_HFS OS Can Be Installed: Yes Media Type: Generic Protocol: SATA SMART Status: Verified Volume UUID: 87D2C53E-7563-3207-B019-528AC90F0B7E Total Size: 32.0 GB (32000000000 Bytes) (exactly 62500000 Blocks) Volume Free Space: 13.7 GB (13705142272 Bytes) (exactly 26767856 Blocks) Device Block Size: 512 Bytes Read-Only Media: No Read-Only Volume: No Ejectable: No Whole: No Internal: Yes Solid State: No
listFilesystems [-plist]	Show the file system personalities available for formaiing in diskutil when using the erasing and partitioning verbs. This is a subset of the complete set of personalities exported by the various filesystem bundles that may be installed in the system. Also shown are some shortcut aliases for common personalities. See the FORMAT section below for more details. If -plist is specified, then a property list instead of the normal user-readable output will be displayed.
unmount umount [force] disk	Unmount a single volume. force will force-unmount the volume (less kind to any open files; see also umount (8)).
unmountDisk umountDisk [force] disk	Unmount an entire disk (all volumes).
eject device	Media will become offline for the purposes of being a data store for file systems or being a member of constructs such as software RAID or direct data. Removable media will become eligible for safe manual removal; automatically-removable media will begin its physical eject sequence.
mount [readOnly] [-mountPoint path] disk	Mount a single volume. readOnly Even the super-user may not write to it; this is the same as the rdonly option to mount (8). -mountPoint path rather than the standard path of /Volumes/VolumeName, will be used as the view into the volume file content; a directory at that path must already exist.
mountDisk disk	Mount all mountable volumes).
rename renameVolume disk name	Volume names are subject to file system-specific alphabet and length restrictions.
enableJournal disk	on an HFS+ volume. This works whether or not the volume is currently mounted (the volume is temporarily mounted if necessary). Ownership of the affected disk is required.
disableJournal [force] disk	Disable journaling on an HFS+ volume. This normally works whether or not the volume is currently mounted (the volume is temporarily mounted if necessary). If the force option is specified, then journaling is disabled directly on disk; in this case, the volume must not be mounted. Ownership of the affected disk is required.
moveJournal external|internal [journalDevice] disk	external causes the creation of a 512MB Apple_Journal partition out of journalDevice and an HFS+ partition will be created out of the remaining space if available; journalDevice must be a partition, not a whole-disk. The journal for device will then be moved externally onto the newly created Apple_Journal partition. internal will move the journal for device back locally.
enableOwnership device	The on-root-disk Volume Database at /var/db/volinfo .database is manipulated such that the User and Group ID seiings of files, directories, and links (file system objects, or "FSOs") on the target volume are taken into account. This seiing for a particular volume is persistent across ejects and injects of that volume as seen by the current OS, even across reboots of that OS, because of the entries in this OS's Volume Database. Note thus that the seiing is not kept on the target disk, nor is it in-memory. For some locations of devices (e.g. internal hard disks), consideration of ownership seiings on FSOs is the default. For others (e.g. plug-in USB disks), it is not. When ownership is disabled, Owner and Group ID seiings on FSOs appear to the user and programs as the current user and group instead of their actual on-disk seiings, in order to make it easy to use a plug-in disk of which the user has physical possession. When ownership is enabled, the Owner and Group ID seiings that exist on the disk are taken into account for determining access, and exact seiings are written to the disk as FSOs are created. A common reason for having to enable ownership is when a disk is to contain FSOs whose User and Group ID seiings, and thus permissions behavior overall, is critically important, such as when the plug-in disk contains system files to be changed or added to. See vsdbutil . Running as root is required.
disableOwnership device	See enableOwnership above. Running as root is required.
verifyVolume device	Verify the data structure of a volume (e.g. fsck). Ownership of the affected disk is required.
repairVolume device	Repair the data structure of a volume (e.g. fsck). Ownership of the affected disk is required. sudo diskutil repairVolume /Volumes/DGERMAN_2GB Password: Started file system repair on disk2s1 DGERMAN_2GB Checking file system ** /dev/disk2s1 ** Phase 1 - Preparing FAT ** Phase 2 - Checking Directories ** Phase 3 - Checking for Orphan Clusters 106 files, 1783744 KiB free (55742 clusters) Volume repair complete Updating boot support partitions for the volume as required Finished file system repair on disk2s1 DGERMAN_2GB
verifyPermissions [-plist] device	Verify the permissions of a Mac OS X boot volume. The data that guides the permissions verification is wriien during the installation process.
repairPermissions [-plist] device	Repair the permissions of a Mac OS X boot volume. The data that guides the permissions repair is wriien during the installation process. Ownership of the affected disk is required.
eraseDisk format name [[APM]Format | [MBR]Format | [GPT]Format] device	Erase an existing disk, removing all volumes and writing out a new partitioning scheme containing one new empty filesystem volume. If the partitioning scheme is not specified, then an appropriate one for the current machine is chosen. Format is discussed below in the section for the partitionDisk verb. Ownership of the affected disk is required.
eraseVolume format name device	Erase an existing volume or write out a new empty filesystem if there was none. Format is discussed below in the section for the partitionDisk verb. Ownership of the affected disk is required.
eraseOptical [quick] device	Erase optical media (CD/RW, DVD/RW, etc.). Quick specifies whether the disc recording system software should do a full erase or a quick erase. Ownership of the affected disk is required.
zeroDisk device	Erase a device, writing zeros to the media. The device can be a whole-disk or a partition. In either case, in order to be useful again, zero'd whole-disks will need to be partitioned, or zero'd partitions will need to be erased (newfs'd), e.g. by using the partitionDisk or eraseDisk verbs. If you desire a more sophisticated erase algorithm or if you need to erase only free space not in use for files, use the secureErase verb. Ownership of the affected disk is required.
randomDisk [times] device	Erase a whole disk, writing random data to the media. Times is the optional (defaults to 1) number of times to write random information. The device can be a whole-disk or a partition. In either case, in order to be useful again, randomized wholedisks will need to be partitioned, or randomized partitions will need to be erased (newfs'd), e.g. by using the partitionDisk or eraseDisk verbs. If you desire a more sophisticated erase algorithm or if you need to erase only free space not in use for files, use the secureErase verb. Ownership of the affected disk is required.
secureErase [freespace] level device	Erase, using a secure method, either a whole-disk (including any and all partitions), or, only the free space (not in use for files) on a currently-mounted volume. Erasing a whole-disk will leave it useless until it is partitioned again. Erasing freespace on a volume will leave it exactly as it was from an end-user perspective, with the exception that it will not be possible to recover deleted files or data using utility software. If you need to erase all contents of a partition but not its hosting whole-disk, use the zeroDisk or randomDisk verbs. Ownership of the affected disk is required. Level should be one of the following: 0 - Single-pass zero-fill erase. 1 - Single-pass random-fill erase. 2 - US DoD 7-pass secure erase. 3 - Gutmann algorithm 35-pass secure erase. 4 - US DoE algorithm 3-pass secure erase.
partitionDisk device [numberOfPartitions] [[APM]Format | [MBR]Format | [GPT]Format] [part1Format part1Name part1Size part2Format part2Name part2Size part3Format part3Name part3Size ...]	(re)Partition a disk, removing all volumes. All volumes on this disk will be destroyed. The device parameter specifies which whole disk is to be partitioned. The optional numberOfPartitions parameter specifies the number of partitions to create; if given then the number of parameter triplets (see below) is expected to match; else, the number of triplets alone given will determine the number of partitions created. The optional partitioning scheme parameter forces a particular partitioning scheme; if not specified, a suitable default is chosen. They are: [APM]Format specifies that an Apple Partition Map scheme should be used. This is the traditional Apple partitioning scheme used to start up a PowerPC-based Macintosh computer, to use the disk as a non-startup disk with any Mac, or to create a multiplatform compatible startup disk. [MBR]Format specifies that a Master Boot Record scheme should be used. This is the DOS/Windows-compatible partitioning scheme. [GPT]Format specifies that a GUID Partitioning Table scheme should be used. This is the partitioning scheme used to start up an Intel-based Macintosh computer. For each partition, a triplet of the desired filesystem format, volume name, and size must be specified. Several other diskutil verbs allow these triplets as well (and for them, the numberOfPartitions parameter is also optional). The triplets must be as follows: Format names are of the form HFS+, MS-DOS, etc.; a list of formatable filesystems and common aliases is available from the listFilesystems verb. You can specify Free Space to skip an area of the disk. Format guides diskutil both in what partition type to set for the partitions (slices) as well as what filesystem structures to lay down therein, e.g. with the appropriate newfs_* (8). Names are the initial volume names; they must conform to filesystem-specific restrictions. If a name of %noformat% is specified, then the partition is left blank such that the partition space is carved out, the partition type is set according to the filesystem format name, the partition space is partially erased, but a filesystem structure is not laid down; this is useful in certain cases e.g. when seiing up ZFS pools. For Free Space triplets, names are ignored but dummy names must be present. Sizes are floating point numbers followed by a leier or percent sign as described in the sizes section at the end of this page (e.g. 165536000B, 55.3T, 678M, 75%, R). The last partition may be lengthened to the end of the disk. You can specify an exact size for your last partition by specifying it as the penultimate triplet and specifying an additional (last) triplet as Free Space. Ownership of the affected disk is required.
resizeVolume device size [numberOfPartitions] [part1Format part1Name part1Size part2Format part2Name part2Size part3Format part3Name part3Size ...]	Non-destructively resize a volume. You may increase or decrease its size. A size of limits will print the range of valid values for the current filesystem. When decreasing the size, new partitions may optionally be created to fill the newly-freed space. To do this, specify the numberOfPartitions, format, name, and size parameters in the same manner as the triplet description for the partitionDisk verb. Resizing a volume that is currently set as the computer's startup disk will invalidate that seiing; use the Startup Disk System Preferences panel or bless (8) to reset the resized volume as the startup disk. Device refers to a volume; the volume's file system must be journaled HFS+. Valid sizes are a number followed by a capital leier multiplier or percent sign suffix as described in the sizes section at the end of this page (e.g. 1.5T, 128M, 50%). Ownership of the affected disk is required.
splitPartition device [numberOfPartitions] [part1Format part1Name part1Size part2Format part2Name part2Size part3Format part3Name part3Size ...]	Destructively split a volume into multiple partitions. You must supply a list of new partitions to create in the space of the old partition; specify these with the numberOfPartitions, format, name, and size parameters in the same manner as the triplet description for the partitionDisk verb. Device refers to a volume. Ownership of the affected disk is required.
mergePartitions [force] format name fromDevice toDevice	Merge two or more partitions on a disk. All data on merged partitions other than the first will be lost. The first will be erased if it doesn't have a resizable type (e.g. JHFS+) or if the force argument is given. Format and name apply only when the first partition is being erased. Merged partitions are required to be ordered sequentially on disk (see diskutil list for the actual on-disk ordering). Ownership of the affected disk is required.
appleRAID raidVerb [...]	AppleRAID verbs can be used to create, manipulate and destroy AppleRAID volumes (Software RAID). AppleRAID supports three basic types of RAID sets: "stripe" - Striped Volume (RAID 0) "mirror" - Mirrored Volume (RAID 1) "concat" - Concatenated Volume (ining) Of these three basic types, only the "mirror" type increases fault-tolerance. Mirrors may have more than two disks to further increase their fault-tolerance. Striped and concatentated volumes are, in fact, more vulnerable to faults than single disk volumes. From these basic types, "stacked" or "nested" RAID volumes can be created. Stacked RAID sets that make use of mirrored RAID sets are fault-tolerant. For example, these are some of the more common combinations of stacked RAID sets: RAID 50 - A striped RAID set of hardware RAID 5 disks. RAID 10 - A striped RAID set of mirrored RAID sets. RAID 0+1 - A mirrored RAID set of striped RAID sets. Concatenated Mirror - A concatenation of mirrored RAID sets. When creating new RAID sets or adding disks, if possible, it is beier to specify the entire disk instead of a partition on that disk. This allows the software to reformat the entire disk using the most current partition layouts. When using whole disks, the type of partitioning used is selected based on the platform type (PPC = APMFormat, Intel = GPTFormat). GPT and APM partition formats cannot be mixed in the same RAID set. In addition to whole disk and partition device names, AppleRAID uses UUIDs to refer to existing RAID sets and their members. Existing RAID sets may also be specified by mount point (e.g. /Volume/raidset). In many cases, using the UUID for the device argument is preferred because disk device names may change over time when disks are added, disks are removed or when the system is rebooted. If RAID members have been physically disconnected from the system or are no longer responding, you must use the member's UUID as the command argument. Messages in the system log will refer to RAID sets and their member disks by UUID. For more information on specifying device arguments see the "DEVICES" section below. AppleRAID is not a replacement for backing up your data. Backups should be always be performed on a regular basis and before modifying any RAID set using these commands. The following is a list of raidVerb sub-verbs with their descriptions and individual arguments.
list [UUID]	Display AppleRAID volumes with current status and associated member disks. If UUID is specified, only list that RAID. diskutil listRAID is a deprecated synonym for diskutil appleRAID list.
create mirror|stripe|concat setName format devices ...	Create a new RAID set consisting of multiple disks and/or RAID sets. setName is used for both the name of the created RAID volume and the RAID set itself (as displayed in list). e.g. 'diskutil createRAID stripe MyArray JHFS+ disk1 disk2 disk3 disk4'. Ownership of the affected disks is required. diskutil createRAID is a deprecated synonym for diskutil appleRAID create.
delete raidVolume	Destroy an existing RAID set. If the RAID set is a mirror with a resizable filesystem, delete will aiempt to convert each of the member partitions back into a non-RAID volume while retaining the contained filesystem. For concatenated RAID sets with a resizable filesystem, delete will aiempt to shrink the filesystem to fit on the first member partition and convert that to a non-RAID volume. Ownership of the affected disks is required. diskutil destroyRAID is a deprecated synonym for diskutil appleRAID delete.
repairMirror raidVolume newDevice	Repair a degraded mirror by replacing a broken or missing member. Broken devices in the mirrored set can also be rebuilt by specifying newDevice. When replacing members of a mirrored set, the new disk must be the same size or larger than the existing disks in the RAID set. Ownership of the affected disk is required. diskutil repairMirror is a deprecated synonym for diskutil appleRAID repairMirror.
add type newDevice raidVolume	Add a new member or hot spare to an existing RAID set. Type can be either member or spare. New disks are added live, the RAID volume does not need to be unmounted. Mirrored volumes support adding both members and hot spares, concatenated volumes only support adding members. When adding to a mirrored RAID set, the new disk must be the same size or larger than the existing disks in the RAID set. Adding a hot spare to a mirror will enable autorebuilding for that mirror. Adding a new member to a concatenated RAID set appends the member and expands the RAID volume. Ownership of the affected disk is required. diskutil addToRAID is a deprecated synonym for diskutil appleRAID add.
remove oldDevice raidVolume	Remove a member or spare from an existing RAID set. Old disks are removed live, the RAID volume does not need to be unmounted. For missing devices, oldDevice must be the device's UUID. Online mirror members with a resizable filesystem will be converted to non-RAID volumes, spare and offline members will be marked free. For concatenated RAID sets, only the last member can be removed. For resizable filesystems remove will first aiempt to shrink the concatenated RAID set so that the filesystem fits on the remaining disks. Ownership of the affected disk is required. diskutil removeFromRAID is a deprecated synonym for diskutil appleRAID remove.
enable mirror|concat device	Convert a non-RAID disk partition containing a resizable filesystem (like JHFS+) into an unpaired mirror or single disk concatenated RAID set. Disks that were originally partitioned on Mac OS X 10.2 Jaguar or earlier or were partitioned to be Mac OS 9 compatible may not be resizable. Ownership of the affected disk is required. diskutil enableRAID is a deprecated synonym for diskutil appleRAID enable.
update key value raidVolume	Update the key value parameters of an existing RAID set. Valid keys are: AutoRebuild - If true, the system aiempts to rebuild degraded mirrored volumes automatically. When looking for devices for rebuild, AppleRAID first looks for hot spares and then degraded members. Use a value of "1" for true and "0" for false. Seiimeout - Controls how long the system waits (in seconds) for a missing device before degrading a mirrored raid set. Also controls the amount of time you have to disconnect all devices from an unmounted mirror without degrading it. Ownership of the affected disk is required. diskutil updateRAID is a deprecated synonym for diskutil appleRAID update.

disk reference

• disk identifier disk*, e.g. disk1s9.
• device node entry containing the disk identifier. /dev/disk*, e.g. /dev/disk2.
• volume mount point. /Volumes/*, e.g. /Volumes/Untitled.
• Universally Unique Identifier or UUID. e.g. 11111111-2222-3333-4444-555555555555.

DISK IDENTIFIER

• U is the device unit. It may refer to hardware (e.g. a hard drive, optical drive, or memory card) or a "drive" constructed by software (e.g. an AppleRAID set or a disk image).
• Q is the session and is only included for optical media; it refers to the number of times recording has taken place on the currently-inserted medium (disc).
• S is the slice; it refers to a partition. Upon this partition, the raw data that underlies a user-visible file system is usually present, but it may also contain specialized data for certain 3rd-party database programs, or data required for the system software (e.g. EFI or booter partitions, or APM partition map data).

The forms diskUsQ and diskUsS appear the same and must be distinguished by context.
For non-optical media, this two-part form identifies a slice upon which (filesystem) data is stored.
For optical media, it identifies a session upon which a partitioning scheme (with its slices with filesystems) is stored.

SIZES

• B is bytes (not blocks)
• S is 512-byte blocks (device-independent)
• K kilobytes 1,000 (10^3).
• M megabytes 1,000,000 (10^6).
• G gigabytes 1,000,000,000 (10^9).
• T terabytes 1,000,000,000,000 , a thousand GB(10^12).
• P petabytes 1,000,000,000000000 , a Million GB (10^15).

• nn%
• R specifies the remainder of the whole-disk. It need not be in the last triplet. It must only appear in at most one triplet in the group of triplets.

FORMAT

     msdos.util [-m mountflag1 mountflag2 mountflag3 mountflag4] device node

     msdos.util [-p mountflag1 mountflag2 mountflag3 mountflag4] device

     msdos.util [-u] device

     msdos.util [-n] device name

     The msdos.util command supports the mounting, probing, and unmounting of FAT file systems.

           -m mountflag1 mountflag2 mountflag3 mountflag4 mount
           -n          set name
           -p mountflag1 mountflag2 mountflag3 mountflag4 probe for mounting
           -u          unmount

     mountflags :
           o   removable or fixed
           o   readonly or writeable
           o   suid or nosuid
           o   dev or nodev 

     fsck_msdos -- DOS/Windows (FAT) file system consistency check

     fsck_msdos -q special ...
     fsck_msdos -p [-f] special ...
     fsck_msdos [-fny] special ...

     verifies and repairs FAT file systems (more commonly known as DOS file systems).

     -p normally started by fsck(8) run
     from /etc/rc.boot during automatic reboot, when a FAT file system is detected.  When preening file sys-
     tems, fsck_msdos will fix common inconsistencies non-interactively.  If more serious problems are
     found, fsck_msdos does not try to fix them, indicates that it was not successful, and exits.

           -q      Causes fsck_msdos to quickly check whether the volume was unmounted cleanly.  If the vol-
                   ume was unmounted cleanly, then the exit status is 0.  If the volume was not unmounted
                   cleanly, then the exit status will be non-zero.  In either case, a message is printed to
                   standard output describing whether the volume was clean or dirty.

           -f      ignored 

           -n      Causes fsck_msdos to assume no as the answer to all operator questions, except ``CONTINUE?''.  
           -p      Preen the specified file systems.  
           -y      Causes fsck_msdos to assume yes as the answer to all operator questions.