Ubuntu Manpage: git-lfs-migrate - Migrate history to or from Git LFS

NAME

       git-lfs-migrate - Migrate history to or from Git LFS

SYNOPSIS

       git lfs migrate <mode> [options] [--] [branch ...]

DESCRIPTION

       Convert files in a Git repository to or from Git LFS pointers, or summarize Git file sizes by file type.
       The import mode converts Git files (i.e., blobs) to Git LFS, while the export mode does the reverse, and
       the info mode provides an informational summary which may be useful in deciding which files to import or
       export.

       In all modes, by default git lfs migrate operates only on the currently checked-out branch, and only on
       files (of any size and type) added in commits which do not exist on any remote. Multiple options are
       available to override these defaults.

       When converting files to or from Git LFS, the git lfs migrate command will only make changes to your
       local repository and working copy, never any remotes. This is intentional as the import and export modes
       are generally "destructive" in the sense that they rewrite your Git history, changing commits and
       generating new commit SHAs. (The exception is the "no-rewrite" import sub-mode; see IMPORT WITHOUT
       REWRITING HISTORY for details.)

       You should therefore always first commit or stash any uncommitted work before using the import or export
       modes, and then validate the result of the migration before pushing the changes to your remotes, for
       instance by running the info mode and by examining your rewritten commit history.

       Once you are satisfied with the changes, you will need to force-push the new Git history of any rewritten
       branches to all your remotes. This is a step which should be taken with care, since you will be altering
       the Git history on your remotes.

       To examine or modify files in branches other than the currently checked-out one, branch refs may be
       specified directly, or provided in one or more --include-ref options. They may also be excluded by
       prefixing them with ^ or providing them in --exclude-ref options. Use the --everything option to specify
       that all refs should be examined, including all remote refs. See INCLUDE AND EXCLUDE REFERENCES for
       details.

       For the info and import modes, all file types are considered by default; while useful in the info mode,
       this is often not desirable when importing, so either filename patterns (pathspecs) or the --fixup option
       should normally be specified in that case. (At least one include pathspec is required for the export
       mode.) Pathspecs may be defined using the --include and --exclude options (-I and -X for short), as
       described in INCLUDE AND EXCLUDE.

       As typical Git LFS usage depends on tracking specific file types using filename patterns defined in
       .gitattributes files, the git lfs migrate command will examine, create, and modify .gitattributes files
       as necessary. The .gitattributes files will always be assigned the default read/write permissions mode
       (i.e., without execute permissions). Any symbolic links with that name will cause the migration to halt
       prematurely.

       The import mode (see IMPORT) will convert Git objects of the file types specified (e.g., with --include)
       to Git LFS pointers, and will add entries for those file types to .gitattributes files, creating those
       files if they do not exist. The result should be as if git lfs track commands had been run at the points
       in your Git history corresponding to where each type of converted file first appears. The exception is if
       the --fixup option is given, in which case the import mode will only examine any existing .gitattributes
       files and then convert Git objects which should be tracked by Git LFS but are not yet.

       The export mode (see EXPORT) works as the reverse operation to the import mode, converting any Git LFS
       pointers that match the file types specified with --include, which must be given at least once. Note that
       .gitattributes entries will not be removed, nor will the files; instead, the export mode inserts "do not
       track" entries similar to those created by the git lfs untrack command. The --remote option is available
       in the export mode to specify the remote from which Git LFS objects should be fetched if they do not
       exist in the local Git LFS object cache; if not provided, origin is used by default.

       The info mode (see INFO) summarizes by file type (i.e., by filename extension) the total number and size
       of files in a repository. Note that like the other two modes, by default the info mode operates only on
       the currently checked-out branch and only on commits which do not exist on any remote, so to get a
       summary of the entire repository across all branches, use the --everything option. If objects have
       already been converted to Git LFS pointers, then by default the size of the referenced objects is totaled
       and reported separately. You may also choose to ignore them by using --pointers=ignore or to treat the
       pointers as files by using --pointers=no-follow. (The latter option is akin to how existing Git LFS
       pointers were handled by the info mode in prior versions of Git LFS).

       When using the --everything option, take note that it means all commits reachable from all refs (local
       and remote) will be considered, but not necessarily all file types. The import and info modes consider
       all file types by default, although the --include and --exclude options constrain this behavior.

       While the --everything option means all commits reachable from any ref will be considered for migration,
       after migration only local refs will be updated even when --everything is specified. This ensures remote
       refs stay synchronized with their remote. In other words, refs/heads/foo will be updated with the
       --everything option, but refs/remotes/origin/foo will not, so it stays in sync with the remote until git
       push origin foo is performed. After checking that the results of a migration with --everything are
       satisfactory, it may be convenient to push all local branches to your remotes by using the --all option
       to git push.

       Unless the --skip-fetch option is given, git lfs migrate always begins by fetching updated lists of refs
       from all the remotes returned by git remote, but as noted above, after making changes to your local Git
       history while converting objects, it will never automatically push those changes to your remotes.

MODES

       info
           Show information about repository size. See INFO.

       import
           Convert Git objects to Git LFS pointers. See IMPORT and IMPORT WITHOUT REWRITING HISTORY

       export
           Convert Git LFS pointers to Git objects. See EXPORT.

OPTIONS

-I <paths>, --include=<paths>
See INCLUDE AND EXCLUDE.

-X <paths>, --exclude=<paths>
See INCLUDE AND EXCLUDE.

--include-ref=<refname>
See INCLUDE AND EXCLUDE REFERENCES.

--exclude-ref=<refname>
See INCLUDE AND EXCLUDE REFERENCES.

--skip-fetch
Assumes that the known set of remote references is complete, and should not be refreshed when
determining the set of "un-pushed" commits to migrate. Has no effect when combined with --include-ref
or --exclude-ref.

--everything
See INCLUDE AND EXCLUDE REFERENCES.

Note: Git refs are "case-sensitive" on all platforms in "packed from" (see git-pack-refs(1)). On
"case-insensitive" file systems, e.g. NTFS on Windows or default APFS on macOS, git-lfs-migrate(1)
would only migrate the first ref if two or more refs are equal except for upper/lower case letters.

--yes
Assume a yes answer to any prompts, permitting noninteractive use. Currently, the only such prompt is
the one asking whether to overwrite (destroy) any working copy changes. Thus, specifying this option
may cause data loss if you are not careful.

[branch ...]
Migrate only the set of branches listed. If not given, git-lfs-migrate(1) will migrate the currently
checked out branch.

References beginning with ^ will be excluded, whereas branches that do not begin with ^ will be
included.

If any of --include-ref or --exclude-ref are given, the checked out branch will not be appended, but
branches given explicitly will be appended.

INFO
The info mode summarizes the sizes of file objects present in the Git history. It supports all the core
migrate options and these additional ones:

--above=<size>
Only count files whose individual filesize is above the given size. size may be specified as a number
of bytes, or a number followed by a storage unit, e.g., "1b", "20 MB", "3 TiB", etc.

If a set of files sharing a common extension has no files in that set whose individual size is above
the given --above no files no entry for that set will be shown.

--top=<n>
Only display the top n entries, ordered by how many total files match the given pathspec. The default
is to show only the top 5 entries. When existing Git LFS objects are found, an extra, separate "LFS
Objects" line is output in addition to the top n entries, unless the --pointers option is used to
change this behavior.

--unit=<unit>
Format the number of bytes in each entry as a quantity of the storage unit provided. Valid units
include: * b, kib, mib, gib, tib, pib - for IEC storage units * b, kb, mb, gb, tb, pb - for SI
storage units

If a --unit is not specified, the largest unit that can fit the number of counted bytes as a whole
number quantity is chosen.

--pointers=[follow|no-follow|ignore]
Treat existing Git LFS pointers in the history according to one of three alternatives. In the default
follow case, if any pointers are found, an additional separate "LFS Objects" line item is output
which summarizes the total number and size of the Git LFS objects referenced by pointers. In the
ignore case, any pointers are simply ignored, while the no-follow case replicates the behavior of the
info mode in older Git LFS versions and treats any pointers it finds as if they were regular files,
so the output totals only include the contents of the pointers, not the contents of the objects to
which they refer.

--fixup
Infer --include and --exclude filters on a per-commit basis based on the .gitattributes files in a
repository. In practice, this option counts any filepaths which should be tracked by Git LFS
according to the repository’s .gitattributes file(s), but aren’t already pointers. The .gitattributes
files are not reported, in contrast to the normal output of the info mode. This option is
incompatible with explicitly given --include, --exclude filters and with any --pointers setting other
than ignore, hence --fixup implies --pointers=ignore if it is not explicitly set.

The format of the output shows the filename pattern, the total size of the file objects (excluding those
below the --above threshold, if one was defined), and the ratio of the number of files above the
threshold to the total number of files; this ratio is also shown as a percentage. For example:

*.gif 93 MB 9480/10504 files(s) 90%
*.png 14 MB 1732/1877 files(s) 92%

By default only the top five entries are shown, but --top allows for more or fewer to be output as
desired.

IMPORT
The import mode migrates objects present in the Git history to pointer files tracked and stored with Git
LFS. It supports all the core migrate options and these additional ones:

--verbose
Print the commit oid and filename of migrated files to STDOUT.

--above=<size>
Only migrate files whose individual filesize is above the given size. size may be specified as a
number of bytes, or a number followed by a storage unit, e.g., "1b", "20 MB", "3 TiB", etc. This
option cannot be used with the --include, --exclude, and --fixup options.

--object-map=<path>
Write to path a file with the mapping of each rewritten commits. The file format is CSV with this
pattern: OLD-SHA,NEW-SHA

--no-rewrite
Migrate objects to Git LFS in a new commit without rewriting Git history. Please note that when this
option is used, the migrate import command will expect a different argument list, specialized options
will become available, and the core migrate options will be ignored. See IMPORT WITHOUT REWRITING
HISTORY.

--fixup
Infer --include and --exclude filters on a per-commit basis based on the .gitattributes files in a
repository. In practice, this option imports any filepaths which should be tracked by Git LFS
according to the repository’s .gitattributes file(s), but aren’t already pointers. This option is
incompatible with explicitly given --include, --exclude filters.

If --no-rewrite is not provided and --include or --exclude (-I, -X, respectively) are given, the
.gitattributes will be modified to include any new filepath patterns as given by those flags.

If --no-rewrite is not provided and neither of those flags are given, the gitattributes will be
incrementally modified to include new filepath extensions as they are rewritten in history.

IMPORT WITHOUT REWRITING HISTORY
The import mode has a special sub-mode enabled by the --no-rewrite flag. This sub-mode will migrate
objects to pointers as in the base import mode, but will do so in a new commit without rewriting Git
history. When using this sub-mode, the base migrate options, such as --include-ref, will be ignored, as
will those for the base import mode. The migrate command will also take a different argument list. As a
result of these changes, --no-rewrite will only operate on the current branch - any other interested
branches must have the generated commit merged in.

The --no-rewrite sub-mode supports the following options and arguments:

-m <message>, --message=<message>
Specifies a commit message for the newly created commit.

[file ...]
The list of files to import. These files must be tracked by patterns specified in the gitattributes.

If --message is given, the new commit will be created with the provided message. If no message is given,
a commit message will be generated based on the file arguments.

EXPORT
The export mode migrates Git LFS pointer files present in the Git history out of Git LFS, converting them
into their corresponding object files. It supports all the core migrate options and these additional
ones:

--verbose
Print the commit oid and filename of migrated files to STDOUT.

--object-map=<path>
Write to path a file with the mapping of each rewritten commit. The file format is CSV with this
pattern: OLD-SHA,NEW-SHA

--remote=<git-remote>
Download LFS objects from the provided git-remote during the export. If not provided, defaults to
origin.

The export mode requires at minimum a pattern provided with the --include argument to specify which files
to export. Files matching the --include patterns will be removed from Git LFS, while files matching the
--exclude patterns will retain their Git LFS status. The export command will modify the .gitattributes to
set/unset any filepath patterns as given by those flags.

INCLUDE AND EXCLUDE

       You can specify that git lfs migrate should only convert files whose pathspec matches the --include glob
       patterns and does not match the --exclude glob patterns, either to reduce total migration time or to only
       migrate part of your repo. Multiple patterns may be given using commas as delimiters.

       Pattern matching is done so as to be functionally equivalent to the pattern matching format of
       .gitattributes. In addition to simple file extension matches (e.g., .gif) patterns may also specify
       directory paths, in which case the path/* format may be used to match recursively.

       Note that this form of pattern matching for the --include and --exclude options used by the git lfs
       migrate command is unique among the suite of git lfs commands. Other commands which also take these
       options, such as git lfs ls-files, use the gitignore(5) form of pattern matching instead.

INCLUDE AND EXCLUDE REFERENCES

       You can specify that git lfs migrate should only convert files added in commits reachable from certain
       references, namely those defined using one or more --include-ref options, and should ignore files in
       commits reachable from references defined in --exclude-ref options.

                   D---E---F
                  /         \
             A---B------C    refs/heads/my-feature
              \          \
               \          refs/heads/main
                \
                 refs/remotes/origin/main

       In the above configuration, the following commits are reachable by each ref:

           refs/heads/main:           C, B, A
           refs/heads/my-feature:     F, E, D, B, A
           refs/remote/origin/main:   A

       The following git lfs migrate options would, therefore, include commits F, E, D, C, and B, but exclude
       commit A:

             --include-ref=refs/heads/my-feature
             --include-ref=refs/heads/main
             --exclude-ref=refs/remotes/origin/main

       The presence of flag --everything indicates that all commits reachable from all local and remote
       references should be migrated (but note that the remote refs themselves will not be updated).

EXAMPLES

   Migrate unpushed commits
       A common use case for the migrate command is to convert large Git objects to LFS before pushing your
       commits. By default, it only scans commits that don’t exist on any remote, so long as the repository is
       non-bare.

       First, run git lfs migrate info to list the file types taking up the most space in your repository:

           $ git lfs migrate info
           migrate: Fetching remote refs: ..., done
           migrate: Sorting commits: ..., done
           migrate: Examining commits: 100% (1/1), done
           *.mp3   284 MB    1/1 files(s)  100%
           *.pdf   42 MB     8/8 files(s)  100%
           *.psd   9.8 MB  15/15 files(s)  100%
           *.ipynb 6.9 MB    6/6 files(s)  100%
           *.csv   5.8 MB    2/2 files(s)  100%

       Now, you can run git lfs migrate import to convert some file types to LFS:

           $ git lfs migrate import --include="*.mp3,*.psd"
           migrate: Fetching remote refs: ..., done
           migrate: Sorting commits: ..., done
           migrate: Rewriting commits: 100% (1/1), done
             main  d2b959babd099fe70da1c1512e2475e8a24de163 -> 136e706bf1ae79643915c134e17a6c933fd53c61
           migrate: Updating refs: ..., done

       If after conversion you find that some files in your working directory have been replaced with Git LFS
       pointers, this is normal, and the working copies of these files can be repopulated with their full
       expected contents by using git lfs checkout.

   Migrate local history
       You can also migrate the entire history of your repository:

           # Check for large files and existing Git LFS objects in your local main branch
           $ git lfs migrate info --include-ref=main

           # Check for large files and existing Git LFS objects in every branch
           $ git lfs migrate info --everything

           # Check for large files in every branch, ignoring any existing Git LFS objects,
           # and listing the top 100 or fewer results
           $ git lfs migrate info --everything --pointers=ignore --top=100

       The same flags will work in import mode:

           # Convert all zip files in your main branch
           $ git lfs migrate import --include-ref=main --include="*.zip"

           # Convert all zip files in every local branch
           $ git lfs migrate import --everything --include="*.zip"

           # Convert all files over 100K in every local branch
           $ git lfs migrate import --everything --above=100Kb

       Note: This will require a force-push to any existing Git remotes. Using the --all option when
       force-pushing may be convenient if many local refs were updated, e.g., after importing to Git LFS with
       the --everything option.

   Migrate without rewriting local history
       You can also migrate files without modifying the existing history of your repository. Note that in the
       examples below, files in subdirectories are not included because they are not explicitly specified.

       Without a specified commit message:

           $ git lfs migrate import --no-rewrite test.zip *.mp3 *.psd

       With a specified commit message:

           $ git lfs migrate import --no-rewrite \
             -m "Import test.zip, .mp3, .psd files in root of repo" \
             test.zip *.mp3 *.psd

   Migrate from Git LFS
       If you no longer wish to use Git LFS for some or all of your files, you can use the export mode to
       convert Git LFS objects into regular Git blobs again.

       The export mode requires at least one --include pathspec, and will download any objects not found locally
       from your origin Git remote, or from the Git remote you specify with the --remote option.

           # Convert all zip Git LFS objects to files in your main branch
           $ git lfs migrate export --include-ref=main --include="*.zip"

           # Convert all zip Git LFS objects to files in every local branch,
           # fetching any object data not cached locally from the my-remote Git remote
           $ git lfs migrate export --everything --include="*.zip" --remote=my-remote

           # Convert all Git LFS objects to files in every local branch
           $ git lfs migrate export --everything --include="*"

       Note: This will require a force-push to any existing Git remotes. Using the --all option when
       force-pushing may be convenient if many local refs were updated, e.g., after exporting from Git LFS with
       the --everything option.