git-lfs-migrate - Man Page

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 (No Rewrite)] 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 (Refs)] 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 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 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. Also note that after importing across all branches with the --everything option (and then checking to ensure the results are satisfactory!) it may be convenient to update multiple branches on 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 (No Rewrite)].

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 (Refs)].

--exclude-ref=refname

See [Include and Exclude (Refs)].

--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 (Refs)].

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.

--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 (No Rewrite)].

--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 (No Rewrite)

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.

Include and Exclude (Refs)

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 local and remote references should be migrated.

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$ git lfs migrate info --everything# 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"$ git lfs migrate import --everything --include="*.zip"$ 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 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

See Also

git-lfs-checkout(1), git-lfs-track(1), git-lfs-untrack(1), gitattributes(5).

Part of the git-lfs(1) suite.

Referenced By

git-lfs(1).

September 2021