'\" t
.\" Title: git-fsck
.\" Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\" Date: 06/01/2011
.\" Manual: Git Manual
.\" Source: Git 1.7.5.4
.\" Language: English
.\"
.TH "GIT\-FSCK" "1" "06/01/2011" "Git 1\&.7\&.5\&.4" "Git Manual"
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.SH "NAME"
git-fsck \- Verifies the connectivity and validity of the objects in the database
.SH "SYNOPSIS"
.sp
.nf
\fIgit fsck\fR [\-\-tags] [\-\-root] [\-\-unreachable] [\-\-cache] [\-\-no\-reflogs]
[\-\-[no\-]full] [\-\-strict] [\-\-verbose] [\-\-lost\-found] [<object>*]
.fi
.sp
.SH "DESCRIPTION"
.sp
Verifies the connectivity and validity of the objects in the database\&.
.SH "OPTIONS"
.PP
<object>
.RS 4
An object to treat as the head of an unreachability trace\&.
.sp
If no objects are given,
\fIgit fsck\fR
defaults to using the index file, all SHA1 references in \&.git/refs/*, and all reflogs (unless \-\-no\-reflogs is given) as heads\&.
.RE
.PP
\-\-unreachable
.RS 4
Print out objects that exist but that aren\(cqt reachable from any of the reference nodes\&.
.RE
.PP
\-\-root
.RS 4
Report root nodes\&.
.RE
.PP
\-\-tags
.RS 4
Report tags\&.
.RE
.PP
\-\-cache
.RS 4
Consider any object recorded in the index also as a head node for an unreachability trace\&.
.RE
.PP
\-\-no\-reflogs
.RS 4
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\(cqt, but are still in that corresponding reflog\&.
.RE
.PP
\-\-full
.RS 4
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\&.
.RE
.PP
\-\-strict
.RS 4
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\&.
.RE
.PP
\-\-verbose
.RS 4
Be chatty\&.
.RE
.PP
\-\-lost\-found
.RS 4
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\&.
.RE
.sp
It tests SHA1 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 \fI\-\-unreachable\fR flag it will also print out objects that exist but that aren\(cqt reachable from any of the specified head nodes\&.
.sp
So for example
.sp
.if n \{\
.RS 4
.\}
.nf
git fsck \-\-unreachable HEAD \e
$(git for\-each\-ref \-\-format="%(objectname)" refs/heads)
.fi
.if n \{\
.RE
.\}
.sp
will do quite a \fIlot\fR 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 \fIgit fsck\fR is happy, you do have a valid tree\&.
.sp
Any corrupt objects you will have to find in backups or other archives (i\&.e\&., you can just remove them and do an \fIrsync\fR with some other site in the hopes that somebody else has the object you have corrupted)\&.
.sp
Of course, "valid tree" doesn\(cqt mean that it wasn\(cqt generated by some evil person, and the end result might be crap\&. git is a revision tracking system, not a quality assurance system ;)
.SH "EXTRACTED DIAGNOSTICS"
.PP
expect dangling commits \- potential heads \- due to lack of head information
.RS 4
You haven\(cqt specified any nodes as heads so it won\(cqt be possible to differentiate between un\-parented commits and root nodes\&.
.RE
.PP
missing sha1 directory \fI<dir>\fR
.RS 4
The directory holding the sha1 objects is missing\&.
.RE
.PP
unreachable <type> <object>
.RS 4
The <type> object <object>, isn\(cqt actually referred to directly or indirectly in any of the trees or commits seen\&. This can mean that there\(cqs another root node that you\(cqre not specifying or that the tree is corrupt\&. If you haven\(cqt missed a root node then you might as well delete unreachable nodes since they can\(cqt be used\&.
.RE
.PP
missing <type> <object>
.RS 4
The <type> object <object>, is referred to but isn\(cqt present in the database\&.
.RE
.PP
dangling <type> <object>
.RS 4
The <type> object <object>, is present in the database but never
\fIdirectly\fR
used\&. A dangling commit could be a root node\&.
.RE
.PP
sha1 mismatch <object>
.RS 4
The database has an object who\(cqs sha1 doesn\(cqt match the database value\&. This indicates a serious data integrity problem\&.
.RE
.SH "ENVIRONMENT VARIABLES"
.PP
GIT_OBJECT_DIRECTORY
.RS 4
used to specify the object database root (usually $GIT_DIR/objects)
.RE
.PP
GIT_INDEX_FILE
.RS 4
used to specify the index file of the index
.RE
.PP
GIT_ALTERNATE_OBJECT_DIRECTORIES
.RS 4
used to specify additional object database roots (usually unset)
.RE
.SH "GIT"
.sp
Part of the \fBgit\fR(1) suite