manpagez: man pages & more
man tmutil(8)
Home | html | info | man
tmutil(8)                 BSD System Manager's Manual                tmutil(8)


     tmutil -- Time Machine utility


     tmutil verb [options]


     tmutil provides methods of controlling and interacting with Time Machine,
     as well as examining and manipulating Time Machine backups. Common abili-
     ties include restoring data from backups, editing exclusions, and compar-
     ing backups.

     Several, but not all, verbs require root privileges.


     Throughout this manual, specific language is used to describe particular
     "realms" associated with Time Machine backups. It is important to under-
     stand this terminology to make effective use of tmutil and its manual.

     backup source
             A volume currently being backed up by Time Machine.

     backup disk
             The HFS+ volume that contains Time Machine backups.

     backup destination
             In the case of a local destination, a synonym for backup disk.
             For network destinations, this is the AFP share on which the
             backup disk image resides.

     backup disk image (or backup image)
             A sparsebundle that, when mounted, is the backing store for a
             volume that is a backup disk.

     backup store
             The top-level "Backups.backupdb" directory at the root of a
             backup disk.

     machine directory
             A directory inside a backup store that contains all the backups
             for a particular computer. For local destinations, a backup store
             can contain multiple machine directories, all for separate com-

             A directory inside a machine directory that represents a single
             initial or incremental backup of one computer. The word "snap-
             shot", in most contexts, is a generic term and is not to be con-
             fused with a "local Time Machine snapshot", which is simply a
             snapshot stored locally on the computer.

     snapshot volume
             A directory inside a snapshot that represents a single initial or
             incremental backup of one backup source. E.g.,

             lae/2011-07-03-123456/Mac HD


     Each verb is listed with its description and individual arguments.

     help [verb]
             Print extended usage for a given verb. If no verb is provided,
             print a list of verbs and usage summaries.

             Turn on automatic backups. Requires root privileges.

             Turn off automatic backups. Requires root privileges.

             Turn on local Time Machine snapshots. Requires root privileges.

             Turn off local Time Machine snapshots and trigger automatic
             cleanup of accumulated local snapshot data. Requires root privi-

             Create new local Time Machine snapshot.

     startbackup [-a | --auto] [-b | --block] [-r | --rotation] [-d |
             --destination dest_id]
             Begin a backup if one is not already running.

                 --auto           Run the backup in a mode similar to system-
                                  scheduled backups.
                 --block          Wait (block) until the backup is finished
                                  before exiting.
                 --rotation       Allow automatic destination rotation during
                                  the backup.
                 --destination    Perform the backup to the destination corre-
                                  sponding to the specified ID.

             The --auto option provides a supported mechanism with which to
             trigger "automatic-like" backups, similar to automatic backups
             that are scheduled by the system. While this is not identical to
             true system-scheduled backups, it provides custom schedulers the
             ability to achieve some (but not all) behavior normally exhibited
             when operating in automatic mode.

             Cancel a backup currently in progress.

     delete path ...
             Delete one or more snapshots, machine directories, or backup
             stores. This verb can delete items from backups that were not
             made by, or are not claimed by, the current machine. Requires
             root privileges.

     restore [-v] src ... dst
             Restore the item src, which is inside a snapshot, to the location
             dst. The dst argument mimics the destination path semantics of
             the cp tool. You may provide multiple source paths to restore.
             The last path argument must be a destination.

             When using the restore verb, tmutil behaves largely like Finder.
             Custom Time Machine metadata (extended security and other) will
             be removed from the restored data, and other metadata will be

             Root privileges are not strictly required to perform restores,
             but tmutil does no permissions preflighting to determine your
             ability to restore src or its descendants. Therefore, depending
             on what you're restoring, you may need root privileges to perform
             the restore, and you should know this ahead of time. This is the
             same behavior you would encounter with other copy tools such as
             cp or ditto. When restoring with tmutil as root, ownership of the
             restored items will match the state of the items in the backup.

     compare [-@esmugtndEUX] [-D depth] [-I name] [snapshot_path | path1
             Perform a backup diff.

             If no arguments are provided, tmutil will compare the computer to
             the latest snapshot. If a snapshot path is provided as the sole
             argument, tmutil will compare the computer to the specified snap-
             shot. If two path arguments are provided, tmutil will compare
             those two items to each other.  tmutil will attempt to inform you
             when you have asked it to do something that doesn't make sense or
             isn't supported.

             The compare verb allows you to specify what properties to com-
             pare. If you specify no property options, tmutil assumes you want
             to analyze standard Time Machine behavior. The default property
             set in this case is equivalent to the -@smugt option set. Speci-
             fying any property option overrides the default set.

                 -a    Compare all supported metadata.
                 -@    Compare extended attributes.
                 -e    Compare ACLs.
                 -s    Compare sizes.
                 -m    Compare file modes.
                 -u    Compare UIDs.
                 -g    Compare GIDs.
                 -t    Compare modification times.
                 -n    No metadata comparison.
                 -d    Compare file data forks.
                 -D    Limit traversal depth to depth levels from the begin-
                       ning of iteration.
                 -E    Don't take exclusions into account when comparing items
                       inside volumes.
                 -I    Ignore paths with a path component equal to name during
                       iteration. This may be specified multiple times.
                 -U    Ignore logical volume identity (volume UUIDs) when
                       directly comparing a local volume or snapshot volume to
                       a snapshot volume.
                 -X    Print output in XML property list format.

     setdestination [-ap] arg
             Configure a local HFS+ volume or AFP share as a backup destina-
             tion. Requires root privileges.

             When the -a option is provided, arg will be added to the list of
             destinations. Time Machine will automatically choose a backup
             destination from the list when performing backups. When the -a
             option is not provided, the current list of destinations will be
             replaced by arg.

             If you wish to set an HFS+ volume as the backup destination, arg
             should be the mount point of the volume in question. When setting
             an AFP destination arg takes the form:


             In the AFP case, the password component of the URL is optional;
             you may instead specify the -p option to enter the password at a
             non-echoing interactive prompt. This is of particular interest to
             the security-conscious, as all arguments provided to a program
             are visible by all users on the system via the ps tool.

     destinationinfo [-X]
             Print information about destinations currently configured for use
             with Time Machine. For each backup destination, the following
             information may be displayed:

                 Name          The volume label as shown in Finder.
                 Kind          Whether the destination is locally attached
                               storage or a network device.
                 URL           In the case of a network destination, the URL
                               used for Time Machine configuration.
                 Mount Point   If the volume is currently mounted, the path in
                               the file system at which it was mounted.
                 ID            The unique identifier for the destination.

             When more than one destination is configured, the most recent
             backup destination will be marked with the > indicator.

             When the -X option is provided, output will be printed in XML
             property list format.

     removedestination identifier
             Remove the destination with the specified unique identifier from
             the Time Machine configuration. Requires root privileges.

             To obtain the unique identifier for a destination, see

     addexclusion [-p] item ...
             Configure an exclusion that tells Time Machine not to back up a
             file, directory, or volume during future backups.

             There are two kinds of user-configurable exclusions in Time
             Machine. The first, which is the default behavior for the
             addexclusion verb, is a location-independent ("sticky") exclusion
             that follows a file or directory. When the file or directory is
             moved, the exclusion goes with the item to the new location.
             Additionally, when the item is copied, the copy retains the

             The second kind of exclusion is what is known as a fixed-path
             exclusion. In this scenario, you tell Time Machine that you want
             a specific path to be excluded, agnostic of the item at that
             path. If there is no file or directory at the specified path, the
             exclusion has no effect; if the item previously at the path has
             been moved or renamed, the item is not excluded, because it does
             not currently reside at the excluded path. As a consequence of
             these semantics, moving a file or directory to the path will
             cause the item to be excluded--fixed-path exclusions are not
             automatically cleaned up when items are moved or deleted and will
             take effect again once an item exists at an excluded path.

             The -p option sets a fixed-path exclusion as described above.
             Requires root privileges.

             Volume exclusions can be set with the addexclusion verb. The -p
             option is ignored for volumes; exclusions set on volumes track
             the volume regardless of volume name or mount path changes. Eras-
             ing the volume will cause it to be included in future backups.
             (See associatedisk.)  Requires root privileges.

     removeexclusion [-p] item ...
             Configure Time Machine to back up a file, directory, or volume
             during future backups. This verb follows the same usage, exclu-
             sion style, and privilege semantics as addexclusion.

     isexcluded [-X] item ...
             Determine if a file, directory, or volume are excluded from Time
             Machine backups.

             When the -X option is provided, output will be printed in XML
             property list format.

             # example output for an excluded item
             thermopylae:~ thoth$ tmutil isexcluded /Users/admin/Desk-
             [Excluded]      /Users/admin/Desktop/foo.txt

             # example output for an item that is not excluded
             thermopylae:~ thoth$ tmutil isexcluded /Users/admin/Desk-
             [Included]      /Users/admin/Desktop/bar.txt

     inheritbackup {machine_directory | sparsebundle}
             Claim a machine directory or sparsebundle for use by the current
             machine. Requires root privileges.

             Machine directories and sparsebundles are owned by one computer
             at a time, and are tracked by unique identifiers rather than com-
             puter name, host name, or ethernet address. The inheritbackup
             verb reassigns the identity of the specified item, reconfiguring
             it so the current host recognizes it during backups. When inher-
             iting a sparsebundle, the machine directory within will also be

             Inheriting is typically only one step in the process of configur-
             ing a backup for use by a machine. You may also need to use
             setdestination, associatedisk, or both, depending on the situa-

             One machine can own multiple machine directories and sparsebun-
             dles, but it is ill-advised for them to reside in the same place.
             In such a situation, which will be chosen during a backup is
             undefined. As a result, inheritbackup will attempt to detect pos-
             sible identity collisions before making changes.

     associatedisk [-a] mount_point snapshot_volume
             Bind a snapshot volume directory to the specified local disk,
             thereby reconfiguring the backup history. Requires root privi-

             In Mac OS X, HFS+ volumes have a persistent UUID that is assigned
             when the file system is created. Time Machine uses this identi-
             fier to make an association between a source volume and a snap-
             shot volume. Erasing the source volume creates a new file system
             on the disk, and the previous UUID is not retained. The new UUID
             causes the source volume -> snapshot volume assocation to be bro-
             ken. If one were just erasing the volume and starting over, it
             would likely be of no real consequence, and the new UUID would
             not be a concern; when erasing a volume in order to clone another
             volume to it, recreating the association may be desired.

             A concrete example of when and how you would use associatedisk:

             After having problems with a volume, you decide to erase it and
             manually restore its contents from a Time Machine backup or copy
             of another nature. (I.e., not via the Mac OS X installer's System
             Restore feature or Migration Assistant.) On your next incremental
             backup, the data will be copied anew, as though none of it had
             been backed up before. Technically, it is true that the data has
             not been backed up, given the new UUID. However, this is probably
             not what you want Time Machine to do. You would then use
             associatedisk to reconfigure the backup so it appears that this
             volume has been backed up previously:

             thermopylae:~ thoth$ sudo tmutil associatedisk [-a] "/Vol-
             umes/MyNewStuffDisk" "/Volumes/Chronoton/Backups.backupdb/ther-

             The result of the above command would associate the snapshot vol-
             ume MyStuff in the specified snapshot with the source volume
             MyNewStuffDisk. The snapshot volume would also be renamed to
             match. The -a option tells associatedisk to find all snapshot
             volumes in the same machine directory that match the identity of
             MyStuff, and then perform the association on all of them.

             Print the path to the most recent snapshot for this computer.

             Print paths for all of this computer's completed snapshots.

             Print the path to the current machine directory for this com-

     calculatedrift machine_directory
             Analyze the snapshots in a machine directory and determine the
             amount of change between each. Averages are printed after all
             snapshots have been analyzed. This may require root privileges,
             depending on the contents of the machine directory.

     uniquesize path ...
             Analyze the specified path and determine its unique size. The
             figure reported by uniquesize represents things that only exist
             in the specified path; things that are hard-linked in other
             places are not tallied.


     In most situations, tmutil exits 0 on success, >0 otherwise.

Mac OS X                         10 April 2013                        Mac OS X

Mac OS X 10.9 - Generated Fri Oct 18 09:06:03 CDT 2013
© 2000-2023
Individual documents may contain additional copyright information.