diskutil(8) BSD System Manager's Manual diskutil(8)

NAME

 diskutil -- modify, verify and repair local disks

SYNOPSIS

 diskutil [quiet] verb [options]

DESCRIPTION

 diskutil manipulates the structure of local disks. It provides informa-
 tion about, and allows the administration of, the partitioning schemes,
 layouts, and formats of disks. This includes hard disks, solid state
 disks, optical discs, CoreStorage volumes, and AppleRAID sets. It gener-
 ally manipulates whole volumes instead of individual files and directo-
 ries.

VERBS

 Each verb is listed with its description and individual arguments.
 list [-plist] [device]
 List disks. If no argument is given, then all disks and all
 of their partitions are listed.
 If -plist is specified, then a property list will be emitted
 instead of the normal user-readable output. If a device is
 specified, then instead of listing all families of whole disks
 and their partitions, only one such family is listed. In that
 case, specifying either the whole disk or any of its slices
 will work.
 A script could interpret the results of the diskutil list
 -plist output and use diskutil info -plist as well as diskutil
 listFilesystems -plist for more detailed information.
 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-bottom 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 | information [-plist] device
 Get detailed information about a specific whole disk or parti-
 tion. If -plist is specified, then a property list instead of
 the normal user-readable output will be emitted.
 activity
 Continuously display system-wide disk manipulation activity as
 reported by the Disk Arbitration framework until interrupted
 with a signal (e.g. by typing Control-C).
 This can be useful to watch system-wide activity of disks com-
 ing on-line or being ejected, volumes on disks being mounted
 or unmounted, volumes being renamed, etc. However, this out-
 put must never be parsed; programs should become Disk Arbitra-
 tion clients instead.
 For debugging information, such as the monitoring of applica-
 tions dissenting (attempting to deny) activities for disks for
 which they have registered an interest, you must use the log-
 ging features of the diskarbitrationd daemon. Programs needing
 this information must become Disk Arbitration clients.
 listFilesystems [-plist]
 Show the file system personalities available for formatting in
 diskutil when using the erasing and partitioning verbs. This
 is a subset of the complete set of personalities exported by
 the various file system bundles that may be installed in the
 system. Also shown are some shortcut aliases for common per-
 sonalities. 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 emitted.
 unmount | umount [force] device
 Unmount a single volume. Force will force-unmount the volume
 (less kind to any open files; see also umount (8)).
 unmountDisk | umountDisk [force] device
 Unmount an entire disk (all volumes). Force will force-
 unmount the volumes (less kind to any open files; see also
 umount (8)). You should specify a whole disk, but all volumes
 of the whole disk are attempted to be unmounted even if you
 specify a partition.
 eject device
 Eject a disk. Media will become offline for the purposes of
 being a data store for file systems or being a member of con-
 structs such as software RAID or direct data. Additionally,
 removable media will become eligible for safe manual removal;
 automatically-removable media will begin its physical (motor-
 ized) eject sequence.
 mount [readOnly] [-mountPoint path] device
 Mount a single volume. If readOnly is specified, then the
 file system is mounted read-only, even if the volume's under-
 lying file system and/or device and/or media supports writing;
 even the super-user may not write to it; this is the same as
 the rdonly option to mount (8). If a -mountPoint is speci-
 fied, then that path, rather than the standard path of /Vol-
 umes/VolumeName, will be used as the view into the volume file
 content; a directory at that path must already exist.
 mountDisk device
 Mount an entire disk (all mountable volumes). You should
 specify a whole disk, but all volumes of the whole disk are
 attempted to be mounted even if you specify a partition.
 rename | renameVolume device name
 Rename a volume. Volume names are subject to file system-spe-
 cific alphabet and length restrictions.
 enableJournal device
 Enable journaling 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] device
 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] device
 external will create 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 parti-
 tion, not a whole-disk. The journal for device will then be
 moved externally onto the newly created Apple_Journal parti-
 tion.
 internal will move the journal for device back locally.
 Moving the journal works whether or not the volume is mounted,
 provided journaling is enabled on that volume. No errors are
 currently supported to flag attempts to move journals on vol-
 umes that do not have journaling enabled. Ownership of the
 affected disk(s) is required.
 enableOwnership device
 Enable ownership of a volume. The on-root-disk Volume Data-
 base at /var/db/volinfo.database is manipulated such that the
 User and Group ID settings of files, directories, and links
 (file system objects, or "FSOs") on the target volume are
 taken into account.
 This setting 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 setting is not kept
 on the target disk, nor is it in-memory.
 For some locations of devices (e.g. internal hard disks), con-
 sideration of ownership settings on FSOs is the default. For
 others (e.g. plug-in USB disks), it is not.
 When ownership is disabled, Owner and Group ID settings on
 FSOs appear to the user and programs as the current user and
 group instead of their actual on-disk settings, in order to
 make it easy to use a plug-in disk of which the user has phys-
 ical possession.
 When ownership is enabled, the Owner and Group ID settings
 that exist on the disk are taken into account for determining
 access, and exact settings 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 set-
 tings, 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 also the vsdbutil command. Running as root is required.
 disableOwnership device
 Disable ownership of a volume. See enableOwnership above.
 Running as root is required.
 verifyVolume device
 Verify the file system data structures of a volume. The
 appropriate fsck program is executed and the volume is left
 mounted or unmounted at it was before the command. Ownership
 of the disk to be verified is required.
 repairVolume device
 Repair the file system data structures of a volume. The
 appropriate fsck program is executed and the volume is left
 mounted or unmounted at it was before the command. Ownership
 of the affected disk is required.
 verifyDisk device
 Verify the partition map layout of a whole disk intended for
 booting or data use on a Macintosh. The checks further
 include, but are not limited to, the integrity of the EFI Sys-
 tem Partition, the integrity of any Core Storage Physical Vol-
 ume partitions, and provisioning of space for boot loaders.
 Ownership of the disk to be verified is required; it must be a
 whole disk and must have a partition map.
 repairDisk device
 Repair the partition map layout of a whole disk intended for
 booting or data use on a Macintosh. The repairs further
 include, but are not limited to, the repair or creation of an
 EFI System Partition, the integrity of any Core Storage Physi-
 cal Volume partitions, and the provisioning of space for boot
 loaders. Ownership of the affected disk is required; it must
 be a whole disk and must have a partition map.
 verifyPermissions [-plist] device
 Verify the permissions of a Mac OS X boot volume. The data
 that guides the permissions verification is written during the
 installation process. Ownership of the disk to be verified is
 required.
 repairPermissions [-plist] device
 Repair the permissions of a Mac OS X boot volume. The data
 that guides the permissions repair is written 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 file system
 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 file system
 if there was none. Format is discussed below in the section
 for the partitionDisk verb. Ownership of the affected disk is
 required.
 reformat device
 Erase an existing volume by writing out a new empty file sys-
 tem of the same personality (type) and with the same volume
 name. 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 [force] 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 (re)parti-
 tioned, or zero'd partitions will need to be (re)formatted
 with a file system, e.g. by using the partitionDisk,
 eraseDisk, or eraseVolume verbs. If you desire a more sophis-
 ticated erase algorithm or if you need to erase only free
 space not in use for files, use the secureErase verb. The
 force parameter causes best-effort, non-error-terminating,
 forced unmounts and shared-mode writes to be attempted; how-
 ever, this is still no guarantee against drivers which claim
 the disk exclusively. In such cases, you may have to first
 unmount all overlying logical volumes (e.g. CoreStorage or
 AppleRAID), or, if a disk is partially damaged in just the
 wrong way, even un-install a kext or erase the disk elsewhere.
 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 ran-
 dom information. The device can be a whole-disk or a parti-
 tion. In either case, in order to be useful again, randomized
 whole-disks will need to be (re)partitioned, or randomized
 partitions will need to be (re)formatted with a file system,
 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:
 o 0 - Single-pass zero-fill erase.
 o 1 - Single-pass random-fill erase.
 o 2 - US DoD 7-pass secure erase.
 o 3 - Gutmann algorithm 35-pass secure erase.
 o 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 parti-
 tions 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:
 o APM[Format] specifies that an Apple Partition Map
 scheme should be used. This is the traditional
 Apple partitioning scheme used to start up a Pow-
 erPC-based Macintosh computer, to use the disk as a
 non-startup disk with any Mac, or to create a multi-
 platform compatible startup disk.
 o MBR[Format] specifies that a Master Boot Record
 scheme should be used. This is the DOS/Windows-com-
 patible partitioning scheme.
 o 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 file system for-
 mat, 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:
 o Format names are of the form HFS+, MS-DOS, etc.; a
 list of formatable file systems (more precisely,
 personalities exported by the installed file system
 bundles) and common aliases is available from the
 listFilesystems verb. Format guides diskutil both
 in what partition type to set for the partitions
 (slices) as well as what file system structures to
 lay down therein, using the file system bundle's
 plist's FormatExecutable setting (which usually
 points to the appropriate formatter program such as
 newfs_hfs (8)). You can also specify a format of
 Free Space to skip an area of the disk. Addition-
 ally, you can specify the partition (personality)
 type manually and directly with a format of %<human-
 readable partition type>% such as %Apple_HFS% or
 %<GPT partition type UUID constant>% such as
 %48465300-0000-11AA-AA11-00306543ECAC%; these imply
 a name of %noformat% (below). Human-readable types
 must be known to the system but UUID types (GPT
 scheme only) can be arbitrary.
 o Names are the initial volume names; they must con-
 form to file system 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 file system format name, the partition space is
 partially erased, but a file system structure is not
 laid down with any file system's formatter program
 (e.g. newfs_hfs (8)); this is useful for setting up
 partitions that will contain user-defined (not nec-
 essarily file system) data. For a triplet whose
 format is Free Space or a directly-specified parti-
 tion type, its name is ignored but a dummy name must
 be present.
 o Sizes are floating point numbers followed by a let-
 ter or percent sign as described in the SIZES sec-
 tion 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 spec-
 ifying it as the penultimate triplet and specifying an addi-
 tional (last) triplet as Free Space.
 Ownership of the affected disk is required.
 resizeVolume device [ limits | R | 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
 target partition, taking into account current file system and
 partition map conditions such as files in use and other
 (immovable) partitions following the target.
 You can grow a volume (back) to its maximum size possible,
 provided no new partitions have been created that are in the
 way, by specifying R for the new volume size. You should use R
 instead of attempting an absolute value such as 100% because
 the latter cannot count partition map overhead.
 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 setting; 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 capi-
 tal letter 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. Data on the
 first partition will be lost as well if the force argument is
 given.
 If force is not given, and the first partition has a resizable
 file system (e.g. JHFS+), the file system will be preserved
 and grown in a data-preserving manner; your format and name
 parameters are ignored in this case. If force is not given,
 and the first partition is not resizable, you are prompted if
 you want to format. You will also be prompted to format if
 the first partition has an (HFS) Allocation Block Size which
 is too small to support the required growth of the first par-
 tition; see the -b option for newfs_hfs (8).
 If force is given, the final resulting partition is always
 (re)formatted. You should do this if you wish to (re)format to
 a new file system type. You will be prompted to confirm.
 Format and name must always be given, but they have an effect
 only when force is given.
 Merged partitions are required to be ordered sequentially on
 disk (see diskutil list for the actual on-disk ordering). All
 partitions in the range, except for the first one, must be
 unmountable. Ownership of the affected disk is required.
 appleRAID | ar raidVerb [...]
 AppleRAID verbs can be used to create, manipulate and destroy
 AppleRAID volumes (Software RAID). AppleRAID supports three
 basic types of RAID sets:
 o "stripe" - Striped Volume (RAID 0)
 o "mirror" - Mirrored Volume (RAID 1)
 o "concat" - Concatenated Volume (Spanning)
 Of these three basic types, only the "mirror" type increases
 fault-tolerance. Mirrors may have more than two disks to fur-
 ther increase their fault-tolerance. Striped and concaten-
 tated 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:
 o RAID 50 - A striped RAID set of hardware RAID 5
 disks.
 o RAID 10 - A striped RAID set of mirrored RAID sets.
 o RAID 0+1 - A mirrored RAID set of striped RAID sets.
 o Concatenated Mirror - A concatenation of mirrored
 RAID sets.
 When creating new RAID sets or adding disks, if possible, it
 is better 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 spec-
 ifying 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 appleRAID sub-verbs with their
 descriptions and individual arguments.
 list [-plist | UUID]
 Display AppleRAID volumes with current status and
 associated member disks. If UUID is specified,
 only list the RAID set with that AppleRAID Set
 UUID. If -plist is specified, then a property list
 will be emitted instead of user-formatted output.
 The -plist and UUID arguments may not both be spec-
 ified. 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 cre-
 ateRAID stripe MyArray JHFS+ disk1 disk2 disk3
 disk4'. Ownership of the affected disks is
 required. diskutil createRAID is a deprecated syn-
 onym for diskutil appleRAID create.
 delete raidVolume
 Destroy an existing RAID set. If the RAID set is a
 mirror with a resizable file system, delete will
 attempt to convert each of the member partitions
 back into a non-RAID volume while retaining the
 contained file system. For concatenated RAID sets
 with a resizable file system, delete will attempt
 to shrink the file system to fit on the first mem-
 ber partition and convert that to a non-RAID vol-
 ume. 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 adding a "new" disk
 given as newDevice to the RAID mirror set whose
 exported disk device or set UUID is given as
 raidVolume. The new disk must be the same size or
 larger than the existing disks in the RAID set.
 After running this command, you should manually
 remove the old (orphaned, failed) member(s) with
 diskutil appleRAID remove. 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 mir-
 rored 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 autore-
 building 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 depre-
 cated 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 file system will be con-
 verted to non-RAID volumes, spare and offline mem-
 bers will be marked free. For concatenated RAID
 sets, only the last member can be removed. For
 resizable file systems remove will first attempt to
 shrink the concatenated RAID set so that the file
 system 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 file system (such as 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. Own-
 ership 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:
 o AutoRebuild - If true, the system
 attempts 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.
 o SetTimeout - 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.
 coreStorage | cs coreStorageVerb [...]
 CoreStorage verbs can be used to create, manipulate and
 destroy CoreStorage volumes.
 CoreStorage maintains a world of virtual disks, somewhat like
 RAID, in which one can easily add or remove imported backing
 store disks, as well as exported usable volumes, to or from a
 pool (or several pools). This provides the user with flexibil-
 ity in allocating their hardware; user or operating system
 data can span multiple physical disks seamlessly, for example.
 Apple CoreStorage defines four types of objects, instances of
 which are uniquely represented by a UUID:
 o Logical Volume Group (LVG)
 o Physical Volume (PV)
 o Logical Volume Family (LVF)
 o Logical Volume (LV)
 The Logical Volume Group (LVG) is the top or "pool" level;
 zero or more may exist during any OS boot time session.
 An LVG imports one or more Physical Volumes (PVs). A PV repre-
 sents a device that feeds the LVG storage space; a PV is nor-
 mally real media but it can be a disk image or even an
 AppleRAID Set. A disk offered to be a PV must be a partition
 and the encompassing scheme must be GPT.
 An LVG exports zero or more Logical Volume Families (LVFs). An
 LVF contains properties which govern and bind together all of
 its descendant Logical Volumes (LVs). These properties provide
 settings for Full Disk Encryption (FDE) (such as whether the
 LVG is encrypted, which users have access, etc) and other ser-
 vices.
 A Logical Volume Family (LVF) exports one or more Logical Vol-
 umes (LVs).
 A Logical Volume (LV) exports a dev node, upon which a file
 system (such as Journaled HFS+) resides.
 For more information on specifying device arguments, see the
 DEVICES section below.
 CoreStorage is not a replacement for backing up your data.
 Backups should be always be performed on a regular basis and
 before modifying any CoreStorage volumes using these commands.
 The following is a list of coreStorage sub-verbs with their
 descriptions and individual arguments.
 list [-plist | UUID]
 Display a tree view of the CoreStorage world for
 all current logical volume groups (LVGs) with mem-
 ber disks (PVs) and exported volumes (LVFs and
 LVs), with properties and status for each level.
 If -plist is specified then a property list will be
 emitted instead of the formatted tree output; the
 UUIDs can be used with the diskutil coreStorage
 information verb to get properties for the object
 represented by that UUID. If UUID is specified
 then an attempt is made to list only that UUID
 (whatever type of CoreStorage object it may repre-
 sent). The -plist and UUID arguments may not both
 be specified.
 info | information [-plist] UUID | device
 Display properties of the CoreStorage object (LVG,
 PV, LVF, or LV) associated with the given CoreStor-
 age UUID or disk.
 convert device [-stdinpassphrase | -passphrase [passphrase]]
 Convert a regular Journaled HFS+ or Case-sensitive
 Journaled HFS+ volume (must be on a partition and
 within a GPT partitioning scheme) into a CoreStor-
 age logical volume.
 If -passphrase is specified, the on-disk bytes will
 be encrypted. You will be prompted for a new
 passphrase interactively, or you can specify the
 passphrase on the command line. Alternatively, if
 you specify -stdinpassphrase the standard input is
 read for the passphrase so that a program could
 execute diskutil and send the passphrase through a
 pipe without having to expose it as a command-line
 parameter.
 The volume must be resizable (the above types are)
 and also mounted. Conversion is done live and in-
 place; targeting the boot volume is supported; as
 much of the conversion as possible is done before
 an eject or reboot is necessary.
 After slightly shrinking the source volume to make
 room for CoreStorage data structures at the end,
 its partition type is changed to Apple_CoreStorage
 and it becomes a CoreStorage Physical Volume. A
 new CoreStorage Logical Volume Group is then cre-
 ated with this Physical Volume as the backing
 store, followed by the creation of a Logical Volume
 Family and Logical Volume pair.
 At this point, the new CoreStorage PV/LVG/LVF/LV
 stack is ready for use, although the "old" mount-
 point must first be unmounted; yet it might not be
 unmountable. This will occur if the target (now the
 PV) is the current boot volume.
 Just before exiting, diskutil coreStorage convert
 will try to unmount the target disk (which is now
 the "old" mount point and the new PV). If success-
 ful (target is not the boot disk), the volume now
 becomes mounted from the LV. If unsuccessful (tar-
 get is the boot disk), a reboot is necessary.
 At this point, if no encryption was specified, all
 is done. Otherwise, the bytes-on-disk will begin to
 be encrypted in-place by CoreStorage automatically
 "in the background" while the PV/LVG/LVF/LV stack
 continues to be usable. Encryption progress may be
 monitored with diskutil coreStorage list.
 When encryption is finished, a passphrase will be
 required the next time the LV is ejected and re-
 attached. If the LV is hosting the boot volume,
 this passphrase requirement will thus occur at the
 next reboot.
 Note that all on-disk data is not secured immedi-
 ately; it is a deliberate process of encrypting all
 on-disk bytes while the CoreStorage driver keeps
 publishing the (usable) LVG/LV.
 Ownership of the affected disk is required.
 revert device | lvUUID [-stdinpassphrase] | [-passphrase
 passphrase] | [-recoverykeychain file]
 Convert a CoreStorage logical volume back to its
 native type. The volume must have been created by
 means of conversion, e.g. with diskutil coreStorage
 convert.
 If the volume was not created with a passphrase,
 then simple ownership of the affected disk is
 required; otherwise, a passphrase must be supplied,
 either interactively or via one of the parameters.
 create | createLVG lvgName devices ...
 Create a CoreStorage logical volume group. The
 disks specified will become the (initial) set of
 physical volumes; more than one may be specified.
 You can specify partitions (which will be re-typed
 to be Apple_CoreStorage) or whole-disks (which will
 be partitioned as GPT and will contain an
 Apple_CoreStorage partition). The resulting LVG
 UUID can then be used with createVolume below. All
 existing data on the drive(s) will be lost. Owner-
 ship of the affected disk is required.
 delete | deleteLVG lvgUUID | lvgName
 Delete a CoreStorage logical volume group. All log-
 ical volume families with their logical volumes are
 removed, the logical volume group is destroyed, and
 the now-orphaned physical volumes are erased and
 partition-typed as Journaled HFS+.
 createVolume | createLV lvgUUID | lvgName type name size
 [-stdinpassphrase | -passphrase [passphrase]]
 Export a new logical volume family, with a new log-
 ical volume under it, out of a CoreStorage logical
 volume group. Type is the file system personality
 to initialize on the new logical volume. Valid
 types are Journaled HFS+ or Case-sensitive Jour-
 naled HFS+ or their aliases. Size is the amount of
 space to allocate from the parent LVG. It is given
 in the same manner as the triplet description for
 the partitionDisk verb, and you can also specify
 with % a percentage of the current size of the LVG.
 If -passphrase or -stdinpassphrase is specified, in
 the same manner as with diskutil coreStorage
 convert above, on-disk data will be stored in an
 encrypted form as the Logical Volume is filled;
 otherwise, the data will remain plain.
 deleteVolume | deleteLV lvUUID | device
 Remove an exported logical volume (and its logical
 volume family as appropriate) from a CoreStorage
 logical volume group. Any data on that logical vol-
 ume will be lost. This operation will thus result
 in an increase in free space in the logical volume
 group.
 It is assumed that the logical volume is used as a
 backing store for a file system; therefore, an
 unmount attempt is made which must suceeed before
 the removal of the logical volume is done.
 encryptVolume | encryptLV lvUUID | device [-stdinpassphrase] |
 [-passphrase passphrase]
 Begin a live background process of encrypting the
 on-disk backing bytes of an existing plain
 CoreStorage logical volume (LV).
 That is, the on-disk bytes that are backing the
 user data are all visited, read, and re-written in
 an encrypted form; this process can take a long
 time (minutes to hours). This process continues
 seamlessly across reboots. The logical volume
 remains usable at all times. When this command
 returns, the operation will be ongoing; you can
 check progress with diskutil coreStorage list.
 The entire logical volume family (LVF) is affected
 since all LVs in an LVF share the same encryption
 settings.
 Any new user data written while this background
 operation is in progress will be in encrypted form.
 Specifying -passphrase or -stdinpassphrase or
 interactively entering a passphrase is mandatory;
 you do so in the same manner as with diskutil
 coreStorage convert above.
 decryptVolume | decryptLV lvUUID | device [-stdinpassphrase] |
 [-passphrase passphrase]
 Begin a live background process of decrypting the
 on-disk backing bytes of an existing encrypted
 CoreStorage logical volume (LV). Bytes are read,
 decrypted, and written back to disk in plain form.
 The LV must be unlocked before beginning this oper-
 ation.
 Like as in diskutil coreStorage encryptVolume
 above, all on-disk bytes are visited and converted,
 the process is seamless across reboots, the logical
 volume remains usable at all times, the entire log-
 ical volume family (LVF) is affected, any new user
 data written will be in plain form, and the opera-
 tion will be ongoing when this command returns.
 Specifying -passphrase or -stdinpassphrase or
 interactively entering a passphrase is mandatory;
 you do so in the same manner as with diskutil
 coreStorage convert above.
 unlockVolume | unlockLV lvUUID [-stdinpassphrase] |
 [-passphrase passphrase] | [-recoverykeychain file]
 Unlock a logical volume and file system, causing it
 to be attached and mounted.
 Data is now accessible in plain form to the file
 system and applications; the on-physical-disk back-
 ing bytes remain in encrypted form.
 The locked state means that the CoreStorage driver
 has not been given authentication information (a
 passphrase) to interpret the encrypted bytes on
 disk and thus export a dev node. This verb unlocks
 a logical volume family (LVF) and its logical vol-
 umes (LVs) by providing that authentication; as the
 LVs thus appear as dev nodes, any file systems upon
 them are automatically mounted.
 To "re-lock" the volume, make it offline again by
 ejecting it, e.g. with diskutil eject.
 Credentials must be supplied. You must either enter
 a passphrase interactively, specify one of the
 -passphrase or -stdinpassphrase parameters in the
 same manner as with diskutil coreStorage convert
 above, or specify that a recovery keychain file be
 used.
 You can specify -recoverykeychain with a path to a
 keychain file. The keychain must be unlocked (see
 security (1)).
 changeVolumePassphrase | passwd lvUUID [-recoverykeychain
 file] [-oldpassphrase oldpassphrase]
 [-newpassphrase newpassphrase] [-stdinpassphrase]
 Change the passphrase of an existing encrypted vol-
 ume. It need not be unlocked nor mounted. The
 parameters, while variously optional, must be given
 in the above order.
 You must authenticate either via the -oldpassphrase
 parameter, via the -stdinpassphrase parameter (with
 newline or eof-terminated data given to stdin), or
 via an interactive prompt (if no parameters are
 given), in the same manner as diskutil coreStorage
 convert above. Alternatively, you can authenticate
 by specifying -recoverykeychain with a path to a
 keychain file.
 A new passphrase must be supplied, again via one of
 the three methods above (interactive,
 -newpassphrase, or -stdinpassphrase).
 If you are supplying both the old and new
 passphrases via stdin, they must be separated with
 a newline character.

DEVICES

 A device parameter to any of the above commands (except where explicitly
 required otherwise) is usually any of the following:
 o The disk identifier (see below). Any entry of the form of
 disk*, e.g. disk1s9.
 o The device node entry containing the disk identifier. Any
 entry of the form of /dev/disk*, e.g. /dev/disk2.
 o The volume mount point. Any entry of the form of /Volumes/*,
 e.g. /Volumes/Untitled.
 o The Universally Unique Identifier or UUID. Any entry of the
 form of e.g. 11111111-2222-3333-4444-555555555555.

DISK IDENTIFIER

 The disk identifier string variously identifies a device unit, a session
 upon that device, or a partition (slice) upon that session. It may take
 the form of diskU, diskUsS, diskUsQ, or diskUsQsS, where U, S, and Q are
 positive decimal integers (possibly multi-digit), and where:
 o 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).
 o 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).
 o S is the slice; it refers to a partition. Upon this partition,
 the raw data that underlies a user-visible file system is usu-
 ally present, but it may also contain specialized data for cer-
 tain 3rd-party database programs, or data required for the sys-
 tem software (e.g. EFI or booter partitions, or APM partition
 map data).
 Some units (e.g. floppy disks, RAID sets) contain file system data upon
 their "whole" device instead of containing a partitioning scheme with
 partitions.
 Note that the forms diskUsQ and diskUsS appear the same and must be dis-
 tinguished by context. For non-optical media, this two-part form identi-
 fies a slice upon which (file system) data is stored. For optical media,
 it identifies a session upon which a partitioning scheme (with its slices
 with file systems) is stored.

SIZES

 Wherever a size is supplied as an output, it is always presented as a
 base-ten approximation with one decimal digit and a base-ten SI multi-
 plier, often accompanied by a precise count in bytes. Scripts should
 refrain from parsing the normal output and use the -plist option instead.
 Wherever a size is to be supplied as an input, you can provide values in
 several different ways, some absolute and some context-sensitive. All
 suffixes described below are interpreted in a case-insensitive manner.
 The "B" is mandatory by itself but optional when combined with an SI or
 IEC multiplier.
 The most common way is to specify absolute values as a decimal number,
 possibly followed by a period and a decimal fraction, followed without
 whitespace with a suffix as follows:
 o B is bytes (not blocks) where the multiplier is 1.
 o K[B] is power of ten kilobytes where the multiplier is 1000 (1
 x 10^3).
 o M[B] is power of ten megabytes where the multiplier is 1000000
 (1 x 10^6).
 o G[B] is power of ten gigabytes where the multiplier is
 1000000000 (1 x 10^9).
 o T[B] is power of ten terabytes where the multiplier is
 1000000000000 (1 x 10^12).
 o P[B] is power of ten petabytes where the multiplier is
 1000000000000000 (1 x 10^15).
 o E[B] is power of ten exabytes where the multiplier is
 1000000000000000000 (1 x 10^18).
 You can also use the following suffixes:
 o S | UAM ("sectors") is 512-byte units (device-independent)
 where the multiplier is always 512.
 o DBS ("device block size") is the device-dependent native block
 size of the encompassing whole disk, if applicable, where the
 multiplier is often 512, but not always; indeed it might not be
 a power of two.
 o Ki[B] is power of two kibibytes where the multiplier is 1024 (1
 x 2^10).
 o Mi[B] is power of two mebibytes where the multiplier is 1048576
 (1 x 2^20).
 o Gi[B] is power of two gibibytes where the multiplier is
 1073741824 (1 x 2^30).
 o Ti[B] is power of two tebibytes where the multiplier is
 1099511627776 (1 x 2^40).
 o Pi[B] is power of two pebibytes where the multiplier is
 1125899906842624 (1 x 2^50).
 o Ei[B] is power of two exbibytes where the multiplier is
 1152921504606846976 (1 x 2^60).
 In certain contexts (such as when specifying partition triplets) you can
 provide a relative value as follows:
 o % (with a preceding number) is a percentage of the whole-disk
 size.
 o R (with no preceding number) specifies the remainder of the
 whole-disk size after all other triplets in the group are taken
 into account. It need not be in the last triplet. It must
 only appear in at most one triplet among all triplets.
 Note again that B refers to bytes and S and UAM refer to a constant mul-
 tiplier of 512; the latter are useful when working with tools such as gpt
 (8) or df (1). Note also that this multiplier is not a "block" size as
 actually implemented by the underlying device driver and/or hardware, nor
 is it an "allocation block", which is a file system's minimum unit of
 backing store usage, often formatting-option-dependent.
 Examples: 10G (10 gigabytes), 4.23tb (4.23 terabytes), 5M (5 megabytes),
 4GiB (exactly 2^32 bytes), 25.4% (25.4 percent of whole disk size).

FORMAT

 The format parameter for the erasing and partitioning verbs is the file
 system personality name. You can determine this name by looking in a
 file system bundle's
 /System/Library/Filesystems/<fs>.fs/Contents/Info.plist or by using the
 listFilesystems verb, which also lists shortcut aliases for common per-
 sonalities (these shortcuts are defined by diskutil for use with it
 only).
 Common examples include JHFS+, MS-DOS, etc.

EXAMPLES

 Erase a disk
 diskutil eraseDisk JHFS+ Untitled disk3
 Erase a volume
 diskutil eraseVolume HFS+ UntitledHFS /Volumes/SomeDisk
 Partition a disk with three partitions
 diskutil partitionDisk disk3 3 HFSX Name1 10G JHFS+ Name2 10G MS-DOS
 NAME3 10G
 Partition a disk with the APM partitioning scheme
 diskutil partitionDisk disk3 APM HFS+ vol1 25% Journaled\ HFS+ vol2 25%
 Journaled\ HFS+ vol3 50% Free\ Space volX 0%
 Partition a disk with the GPT partitioning scheme
 diskutil partitionDisk disk3 GPT HFS+ vol1 25% MS-DOS VOL2 25% HFS+ vol3
 50% Free\ Space volX 0%
 Resize a volume and create a volume after it, using all remaining space
 diskutil resizeVolume /Volumes/SomeDisk 50g MS-DOS DOS 0b
 Resize a volume and leave all remaining space as unused
 diskutil resizeVolume /Volumes/SomeDisk 12g
 Merge two partitions into a new partition
 diskutil mergePartitions JHFS+ not disk1s3 disk1s5
 Split a partition into three new ones
 diskutil splitPartition /Volumes/SomeDisk JHFS+ vol1 12g MS-DOS VOL2 8g
 JHFS+ vol3 0b
 Create a RAID
 diskutil createRAID mirror MirroredVolume JHFS+ disk1 disk2
 Destroy a RAID
 diskutil destroyRAID /Volumes/MirroredVolume
 Repair a damaged RAID
 diskutil repairMirror /Volumes/MirroredVolume disk3
 Convert volume into RAID volume
 diskutil enableRAID mirror /Volumes/ExistingVolume

SEE ALSO

 authopen(1) , hdid(8) , hdiutil(1) , ufs.util(8) , msdos.util(8) ,
 hfs.util(8) , drutil(1) , diskarbitrationd(8) , mount(8) , umount(8) ,
 newfs_hfs(8) , vsdbutil(8) , fsck(8) 

ERRORS

 diskutil will exit with status 0 if successful or 1 if it cannot complete
 the requested operation; this includes cases in which usage text is
 printed. Before diskutil returns with status 1, it prints a message
 which might include an explanation local to diskutil, an error string
 from the DiskManagement or MediaKit frameworks, an underlying POSIX
 error, or some combination.

HISTORY

 The eraseDisk and partitionDisk verbs had an option to add Mac OS 9 driv-
 ers (in partitions designated for that purpose); there was also a
 repairOS9Permissions verb. These have been removed.
 Starting with Mac OS X 10.6, the input and output notation of disk and
 partition sizes use power-of-10 suffixes. In the past this has been
 power-of-2, regardless of the suffix (e.g. G, Gi, GiB) used for display
 or accepted as input.
Mac OS X 13 June 2013 Mac OS X