git-fsck(1) — Linux manual page


GIT-FSCK(1)                    Git Manual                    GIT-FSCK(1)

NAME         top

       git-fsck - Verifies the connectivity and validity of the objects
       in the database

SYNOPSIS         top

       git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
                [--[no-]full] [--strict] [--verbose] [--lost-found]
                [--[no-]dangling] [--[no-]progress] [--connectivity-only]
                [--[no-]name-objects] [<object>*]

DESCRIPTION         top

       Verifies the connectivity and validity of the objects in the

OPTIONS         top

           An object to treat as the head of an unreachability trace.

           If no objects are given, git fsck defaults to using the index
           file, all SHA-1 references in refs namespace, and all reflogs
           (unless --no-reflogs is given) as heads.

           Print out objects that exist but that aren’t reachable from
           any of the reference nodes.

           Print objects that exist but that are never directly used
           (default).  --no-dangling can be used to omit this
           information from the output.

           Report root nodes.

           Report tags.

           Consider any object recorded in the index also as a head node
           for an unreachability trace.

           Do not consider commits that are referenced only by an entry
           in a reflog to be reachable. This option is meant only to
           search for commits that used to be in a ref, but now aren’t,
           but are still in that corresponding reflog.

           Check not just objects in GIT_OBJECT_DIRECTORY
           ($GIT_DIR/objects), but also the ones found in alternate
           object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES or
           $GIT_DIR/objects/info/alternates, and in packed Git archives
           found in $GIT_DIR/objects/pack and corresponding pack
           subdirectories in alternate object pools. This is now
           default; you can turn it off with --no-full.

           Check only the connectivity of reachable objects, making sure
           that any objects referenced by a reachable tag, commit, or
           tree is present. This speeds up the operation by avoiding
           reading blobs entirely (though it does still check that
           referenced blobs exist). This will detect corruption in
           commits and trees, but not do any semantic checks (e.g., for
           format errors). Corruption in blob objects will not be
           detected at all.

           Unreachable tags, commits, and trees will also be accessed to
           find the tips of dangling segments of history. Use
           --no-dangling if you don’t care about this output and want to
           speed it up further.

           Enable more strict checking, namely to catch a file mode
           recorded with g+w bit set, which was created by older
           versions of Git. Existing repositories, including the Linux
           kernel, Git itself, and sparse repository have old objects
           that triggers this check, but it is recommended to check new
           projects with this flag.

           Be chatty.

           Write dangling objects into .git/lost-found/commit/ or
           .git/lost-found/other/, depending on type. If the object is a
           blob, the contents are written into the file, rather than its
           object name.

           When displaying names of reachable objects, in addition to
           the SHA-1 also display a name that describes how they are
           reachable, compatible with git-rev-parse(1), e.g.

           Progress status is reported on the standard error stream by
           default when it is attached to a terminal, unless
           --no-progress or --verbose is specified. --progress forces
           progress status even if the standard error stream is not
           directed to a terminal.


           During fsck git may find issues with legacy data which
           wouldn’t be generated by current versions of git, and which
           wouldn’t be sent over the wire if transfer.fsckObjects was
           set. This feature is intended to support working with legacy
           repositories containing such data.

           Setting fsck.<msg-id> will be picked up by git-fsck(1), but
           to accept pushes of such data set receive.fsck.<msg-id>
           instead, or to clone or fetch it set fetch.fsck.<msg-id>.

           The rest of the documentation discusses fsck.*  for brevity,
           but the same applies for the corresponding receive.fsck.*
           and fetch.<msg-id>.*. variables.

           Unlike variables like color.ui and core.editor the
           receive.fsck.<msg-id> and fetch.fsck.<msg-id> variables will
           not fall back on the fsck.<msg-id> configuration if they
           aren’t set. To uniformly configure the same fsck settings in
           different circumstances all three of them they must all set
           to the same values.

           When fsck.<msg-id> is set, errors can be switched to warnings
           and vice versa by configuring the fsck.<msg-id> setting where
           the <msg-id> is the fsck message ID and the value is one of
           error, warn or ignore. For convenience, fsck prefixes the
           error/warning with the message ID, e.g. "missingEmail:
           invalid author/committer line - missing email" means that
           setting fsck.missingEmail = ignore will hide that issue.

           In general, it is better to enumerate existing objects with
           problems with fsck.skipList, instead of listing the kind of
           breakages these problematic objects share to be ignored, as
           doing the latter will allow new instances of the same
           breakages go unnoticed.

           Setting an unknown fsck.<msg-id> value will cause fsck to
           die, but doing the same for receive.fsck.<msg-id> and
           fetch.fsck.<msg-id> will only cause git to warn.

           The path to a list of object names (i.e. one unabbreviated
           SHA-1 per line) that are known to be broken in a non-fatal
           way and should be ignored. On versions of Git 2.20 and later
           comments (#), empty lines, and any leading and trailing
           whitespace is ignored. Everything but a SHA-1 per line will
           error out on older versions.

           This feature is useful when an established project should be
           accepted despite early commits containing errors that can be
           safely ignored such as invalid committer email addresses.
           Note: corrupt objects cannot be skipped with this setting.

           Like fsck.<msg-id> this variable has corresponding
           receive.fsck.skipList and fetch.fsck.skipList variants.

           Unlike variables like color.ui and core.editor the
           receive.fsck.skipList and fetch.fsck.skipList variables will
           not fall back on the fsck.skipList configuration if they
           aren’t set. To uniformly configure the same fsck settings in
           different circumstances all three of them they must all set
           to the same values.

           Older versions of Git (before 2.20) documented that the
           object names list should be sorted. This was never a
           requirement, the object names could appear in any order, but
           when reading the list we tracked whether the list was sorted
           for the purposes of an internal binary search implementation,
           which could save itself some work with an already sorted
           list. Unless you had a humongous list there was no reason to
           go out of your way to pre-sort the list. After Git version
           2.20 a hash implementation is used instead, so there’s now no
           reason to pre-sort the list.

DISCUSSION         top

       git-fsck tests SHA-1 and general object sanity, and it does full
       tracking of the resulting reachability and everything else. It
       prints out any corruption it finds (missing or bad objects), and
       if you use the --unreachable flag it will also print out objects
       that exist but that aren’t reachable from any of the specified
       head nodes (or the default set, as mentioned above).

       Any corrupt objects you will have to find in backups or other
       archives (i.e., you can just remove them and do an rsync with
       some other site in the hopes that somebody else has the object
       you have corrupted).

       If core.commitGraph is true, the commit-graph file will also be
       inspected using git commit-graph verify. See git-commit-graph(1).


       unreachable <type> <object>
           The <type> object <object>, isn’t actually referred to
           directly or indirectly in any of the trees or commits seen.
           This can mean that there’s another root node that you’re not
           specifying or that the tree is corrupt. If you haven’t missed
           a root node then you might as well delete unreachable nodes
           since they can’t be used.

       missing <type> <object>
           The <type> object <object>, is referred to but isn’t present
           in the database.

       dangling <type> <object>
           The <type> object <object>, is present in the database but
           never directly used. A dangling commit could be a root node.

       hash mismatch <object>
           The database has an object whose hash doesn’t match the
           object database value. This indicates a serious data
           integrity problem.


           used to specify the object database root (usually

           used to specify the index file of the index

           used to specify additional object database roots (usually

GIT         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control
       system) project.  Information about the project can be found at
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       page, see ⟨⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨⟩ on 2021-04-01.  (At that time,
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       (which is not part of the original manual page), send a mail to

Git         04/01/2021                    GIT-FSCK(1)

Pages that refer to this page: git(1)git-config(1)git-fsck(1)git-fsck-objects(1)git-mktag(1)git-prune(1)