GIT-MULTI-PACK-INDEX(1)		  Git Manual	       GIT-MULTI-PACK-INDEX(1)

NAME
       git-multi-pack-index - Write and verify multi-pack-indexes

SYNOPSIS
       git multi-pack-index [--object-dir=<dir>] [--[no-]bitmap] <sub-command>


DESCRIPTION
       Write or verify a multi-pack-index (MIDX) file.

OPTIONS
       --object-dir=<dir>
	   Use given directory for the location of Git objects. We check
	   <dir>/packs/multi-pack-index for the current MIDX file, and
	   <dir>/packs for the pack-files to index.

	   <dir> must be an alternate of the current repository.

       --[no-]progress
	   Turn progress on/off explicitly. If neither is specified, progress
	   is shown if standard error is connected to a terminal. Supported by
	   sub-commands write, verify, expire, and `repack.

       The following subcommands are available:

       write
	   Write a new MIDX file. The following options are available for the
	   write sub-command:

	   --preferred-pack=<pack>
	       When specified, break ties in favor of this pack when there are
	       additional copies of its objects in other packs. Ties for
	       objects not found in the preferred pack are always resolved in
	       favor of the copy in the pack with the highest mtime. If
	       unspecified, the pack with the lowest mtime is used by default.
	       The preferred pack must have at least one object.

	   --[no-]bitmap
	       Control whether or not a multi-pack bitmap is written.

	   --stdin-packs
	       Write a multi-pack index containing only the set of
	       line-delimited pack index basenames provided over stdin.

	   --refs-snapshot=<path>
	       With --bitmap, optionally specify a file which contains a "refs
	       snapshot" taken prior to repacking.

	       A reference snapshot is composed of line-delimited OIDs
	       corresponding to the reference tips, usually taken by git
	       repack prior to generating a new pack. A line may optionally
	       start with a + character to indicate that the reference which
	       corresponds to that OID is "preferred" (see git-config(1)'s
	       pack.preferBitmapTips.)

	       The file given at <path> is expected to be readable, and can
	       contain duplicates. (If a given OID is given more than once, it
	       is marked as preferred if at least one instance of it begins
	       with the special + marker).

	   --incremental
	       Write an incremental MIDX file containing only objects and
	       packs not present in an existing MIDX layer. Migrates
	       non-incremental MIDXs to incremental ones when necessary.
	       Incompatible with --bitmap.

       verify
	   Verify the contents of the MIDX file.

       expire
	   Delete the pack-files that are tracked by the MIDX file, but have
	   no objects referenced by the MIDX (with the exception of .keep
	   packs and cruft packs). Rewrite the MIDX file afterward to remove
	   all references to these pack-files.

	       Note
	       this mode is incompatible with incremental MIDX files.

       repack
	   Create a new pack-file containing objects in small pack-files
	   referenced by the multi-pack-index. If the size given by the
	   --batch-size=<size> argument is zero, then create a pack containing
	   all objects referenced by the multi-pack-index. For a non-zero
	   batch size, Select the pack-files by examining packs from
	   oldest-to-newest, computing the "expected size" by counting the
	   number of objects in the pack referenced by the multi-pack-index,
	   then divide by the total number of objects in the pack and multiply
	   by the pack size. We select packs with expected size below the
	   batch size until the set of packs have total expected size at least
	   the batch size, or all pack-files are considered. If only one
	   pack-file is selected, then do nothing. If a new pack-file is
	   created, rewrite the multi-pack-index to reference the new
	   pack-file. A later run of git multi-pack-index expire will delete
	   the pack-files that were part of this batch.

	   If repack.packKeptObjects is false, then any pack-files with an
	   associated .keep file will not be selected for the batch to repack.

	       Note
	       this mode is incompatible with incremental MIDX files.

EXAMPLES
       •   Write a MIDX file for the packfiles in the current .git directory.

	       $ git multi-pack-index write


       •   Write a MIDX file for the packfiles in the current .git directory
	   with a corresponding bitmap.

	       $ git multi-pack-index write --preferred-pack=<pack> --bitmap


       •   Write a MIDX file for the packfiles in an alternate object store.

	       $ git multi-pack-index --object-dir <alt> write


       •   Verify the MIDX file for the packfiles in the current .git
	   directory.

	       $ git multi-pack-index verify


SEE ALSO
       See The Multi-Pack-Index Design Document[1] and gitformat-pack(5) for
       more information on the multi-pack-index feature and its file format.

GIT
       Part of the git(1) suite

NOTES
	1. The Multi-Pack-Index Design Document
	   file:///usr/share/doc/git-doc/technical/multi-pack-index.html

Git 2.51.0			  2025-08-17	       GIT-MULTI-PACK-INDEX(1)