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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 journalDevice device
                Create a 512MB Apple_Journal partition using the journalDevice
                partition to serve as a journal for the volume device. For
                best results, journalDevice should be a partition on a differ-
                ent whole-disk than the volume itself.

                The journal for device will be moved externally onto the newly
                created Apple_Journal partition.

                Since the journalDevice you specify will invariably be larger
                than 512MB, a new HFS+ partition will be created following the
                Apple_Journal partition to fill the remaining space.

                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.  If you have multi-
                ple volumes for which you want external journals, each must
                have its own external Apple_Journal partition.  Ownership of
                the affected disks is required.

     moveJournal internal device
                Move the journal for device back locally (onto that same
                device).  Ownership of the affected disk 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(8) 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 formattable 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) or 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 and diskutil checkRAID
                           are deprecated synonyms 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
                           or a keychain file in the same manner as diskutil
                           coreStorage unlockVolume.

                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+.

                rename | renameLVG lvgUUID | lvgName newName
                           Rename a CoreStorage logical volume group. Do not
                           confuse this name with the LV name or the volume
                           name of the fiesystem volume on the LV.

                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 currently remaining
                           unallocated space in 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.

                           Credentials must be supplied; you can use
                           -passphrase or -stdinpassphrase or specify that a
                           recovery keychain file be used, in the same manner
                           as diskutil coreStorage unlockVolume.

                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) for more information.

                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                          2 June 2014                         Mac OS X

OS X 10.10 - Generated Thu Nov 6 20:57:02 CST 2014