GIT-BACKFILL(1)			  Git Manual		       GIT-BACKFILL(1)

NAME
       git-backfill - Download missing objects in a partial clone

SYNOPSIS
       git backfill [--min-batch-size=<n>] [--[no-]sparse]


DESCRIPTION
       Blobless partial clones are created using git clone --filter=blob:none
       and then configure the local repository such that the Git client avoids
       downloading blob objects unless they are required for a local
       operation. This initially means that the clone and later fetches
       download reachable commits and trees but no blobs. Later operations
       that change the HEAD pointer, such as git checkout or git merge, may
       need to download missing blobs in order to complete their operation.

       In the worst cases, commands that compute blob diffs, such as git
       blame, become very slow as they download the missing blobs in
       single-blob requests to satisfy the missing object as the Git command
       needs it. This leads to multiple download requests and no ability for
       the Git server to provide delta compression across those objects.

       The git backfill command provides a way for the user to request that
       Git downloads the missing blobs (with optional filters) such that the
       missing blobs representing historical versions of files can be
       downloaded in batches. The backfill command attempts to optimize the
       request by grouping blobs that appear at the same path, hopefully
       leading to good delta compression in the packfile sent by the server.

       In this way, git backfill provides a mechanism to break a large clone
       into smaller chunks. Starting with a blobless partial clone with git
       clone --filter=blob:none and then running git backfill in the local
       repository provides a way to download all reachable objects in several
       smaller network calls than downloading the entire repository at clone
       time.

       By default, git backfill downloads all blobs reachable from the HEAD
       commit. This set can be restricted or expanded using various options.

       THIS COMMAND IS EXPERIMENTAL. ITS BEHAVIOR MAY CHANGE IN THE FUTURE.

OPTIONS
       --min-batch-size=<n>
	   Specify a minimum size for a batch of missing objects to request
	   from the server. This size may be exceeded by the last set of blobs
	   seen at a given path. The default minimum batch size is 50,000.

       --[no-]sparse
	   Only download objects if they appear at a path that matches the
	   current sparse-checkout. If the sparse-checkout feature is enabled,
	   then --sparse is assumed and can be disabled with --no-sparse.

SEE ALSO
       git-clone(1).

GIT
       Part of the git(1) suite

Git 2.51.0			  2025-08-17		       GIT-BACKFILL(1)