GIT-FSCK(1)GIT-FSCK(1)NAMEgit-fsck - Verifies the connectivity and validity of the objects in the
database
SYNOPSIS
git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
[--[no-]full] [--strict] [--verbose] [--lost-found] [<object>*]
DESCRIPTION
Verifies the connectivity and validity of the objects in the database.
OPTIONS
<object>
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 SHA1 references in .git/refs/*, and all reflogs
(unless --no-reflogs is given) as heads.
--unreachable
Print out objects that exist but that aren’t readable from
any of the reference nodes.
--root Report root nodes.
--tags Report tags.
--cache
Consider any object recorded in the index also as a head node
for an unreachability trace.
--no-reflogs
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.
--full 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 subdirec-
tories in alternate object pools. This is now default; you can
turn it off with --no-full.
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GIT-FSCK(1)GIT-FSCK(1)--strict
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.
--verbose
Be chatty.
--lost-found
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.
It tests SHA1 and general object sanity, and it does full track-
ing 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 readable from any of the specified
head nodes.
So for example
git fsck --unreachable HEAD \
$(git for-each-ref --format="%(objectname)" refs/heads)
will do quite a lot of verification on the tree. There are a few
extra validity tests to be added (make sure that tree objects
are sorted properly etc), but on the whole if git fsck is happy,
you do have a valid tree.
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).
Of course, "valid tree" doesn’t mean that it wasn’t
generated by some evil person, and the end result might be crap.
git is a revision tracking system, not a quality assurance sys-
tem ;)
EXTRACTED DIAGNOSTICS
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GIT-FSCK(1)GIT-FSCK(1)
expect dangling commits - potential heads - due to lack of head infor-
mation
You haven’t specified any nodes as heads so it won’t
be possible to differentiate between un-parented commits and
root nodes.
missing sha1 directory <dir>
The directory holding the sha1 objects is missing.
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 pre-
sent 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.
sha1 mismatch <object>
The database has an object who’s sha1 doesn’t match
the database value. This indicates a serious data integrity
problem.
ENVIRONMENT VARIABLES
GIT_OBJECT_DIRECTORY
used to specify the object database root (usually
$GIT_DIR/objects)
GIT_INDEX_FILE
used to specify the index file of the index
GIT_ALTERNATE_OBJECT_DIRECTORIES
used to specify additional object database roots (usually unset)
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org: mailto:torvalds@osdl.org>
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GIT-FSCK(1)GIT-FSCK(1)DOCUMENTATION
Documentation by David Greaves, Junio C Hamano and the git-list
<git@vger.kernel.org: mailto:git@vger.kernel.org>.
GIT
Part of the git(1) suite
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