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HTML rendering created 2026-01-16 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | COMMANDS | RECOMMENDED CONFIG VALUES | SEE ALSO | GIT | COLOPHON |
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SCALAR(1) Git Manual SCALAR(1)
scalar - A tool for managing large Git repositories
scalar clone [--single-branch] [--branch <main-branch>] [--full-clone]
[--[no-]src] [--[no-]tags] [--[no-]maintenance] <url> [<enlistment>]
scalar list
scalar register [--[no-]maintenance] [<enlistment>]
scalar unregister [<enlistment>]
scalar run ( all | config | commit-graph | fetch | loose-objects | pack-files ) [<enlistment>]
scalar reconfigure [--maintenance=(enable|disable|keep)] [ --all | <enlistment> ]
scalar diagnose [<enlistment>]
scalar delete <enlistment>
Scalar is a repository management tool that optimizes Git for use
in large repositories. Scalar improves performance by configuring
advanced Git settings, maintaining repositories in the background,
and helping to reduce data sent across the network.
An important Scalar concept is the enlistment: this is the
top-level directory of the project. It usually contains the
subdirectory src/ which is a Git worktree. This encourages the
separation between tracked files (inside src/) and untracked
files, such as build artifacts (outside src/). When registering an
existing Git worktree with Scalar whose name is not src, the
enlistment will be identical to the worktree.
The scalar command implements various subcommands, and different
options depending on the subcommand. With the exception of clone,
list and reconfigure --all, all subcommands expect to be run in an
enlistment.
The following options can be specified before the subcommand:
-C <directory>
Before running the subcommand, change the working directory.
This option imitates the same option of git(1).
-c <key>=<value>
For the duration of running the specified subcommand,
configure this setting. This option imitates the same option
of git(1).
Clone
clone [<options>] <url> [<enlistment>]
Clones the specified repository, similar to git-clone(1). By
default, only commit and tree objects are cloned. Once
finished, the worktree is located at <enlistment>/src.
The sparse-checkout feature is enabled (except when run with
--full-clone) and the only files present are those in the
top-level directory. Use git sparse-checkout set to expand the
set of directories you want to see, or git sparse-checkout
disable to expand to all files (see git-sparse-checkout(1) for
more details). You can explore the subdirectories outside your
sparse-checkout by using git ls-tree HEAD[:<directory>].
-b <name>, --branch <name>
Instead of checking out the branch pointed to by the cloned
repository’s HEAD, check out the <name> branch instead.
--single-branch, --no-single-branch
Clone only the history leading to the tip of a single branch,
either specified by the --branch option or the primary branch
remote’s HEAD points at.
Further fetches into the resulting repository will only update
the remote-tracking branch for the branch this option was used
for the initial cloning. If the HEAD at the remote did not
point at any branch when --single-branch clone was made, no
remote-tracking branch is created.
--src, --no-src
By default, scalar clone places the cloned repository within a
<entlistment>/src directory. Use --no-src to place the cloned
repository directly in the <enlistment> directory.
--tags, --no-tags
By default, scalar clone will fetch the tag objects advertised
by the remote and future git fetch commands will do the same.
Use --no-tags to avoid fetching tags in scalar clone and to
configure the repository to avoid fetching tags in the future.
To fetch tags after cloning with --no-tags, run git fetch
--tags.
--full-clone, --no-full-clone
A sparse-checkout is initialized by default. This behavior can
be turned off via --full-clone.
--maintenance, --no-maintenance
By default, scalar clone configures the enlistment to use
Git’s background maintenance feature. Use the --no-maintenance
to skip this configuration.
List
list
List enlistments that are currently registered by Scalar. This
subcommand does not need to be run inside an enlistment.
Register
register [<enlistment>]
Adds the enlistment’s repository to the list of registered
repositories and starts background maintenance. If
<enlistment> is not provided, then the enlistment associated
with the current working directory is registered.
Note: when this subcommand is called in a worktree that is
called src/, its parent directory is considered to be the
Scalar enlistment. If the worktree is not called src/, it
itself will be considered to be the Scalar enlistment.
--maintenance, --no-maintenance
By default, scalar register configures the enlistment to use
Git’s background maintenance feature. Use the --no-maintenance
to skip this configuration. This does not disable any
maintenance that may already be enabled in other ways.
Unregister
unregister [<enlistment>]
Remove the specified repository from the list of repositories
registered with Scalar and stop the scheduled background
maintenance.
Run
scalar run ( all | config | commit-graph | fetch | loose-objects |
pack-files ) [<enlistment>]
Run the given maintenance task (or all tasks, if all was
specified). Except for all and config, this subcommand simply
hands off to git-maintenance(1) (mapping fetch to prefetch and
pack-files to incremental-repack).
These tasks are run automatically as part of the scheduled
maintenance, as soon as the repository is registered with
Scalar. It should therefore not be necessary to run this
subcommand manually.
The config task is specific to Scalar and configures all those
opinionated default settings that make Git work more
efficiently with large repositories. As this task is run as
part of scalar clone automatically, explicit invocations of
this task are rarely needed.
Reconfigure
After a Scalar upgrade, or when the configuration of a Scalar
enlistment was somehow corrupted or changed by mistake, this
subcommand allows to reconfigure the enlistment.
--all
When --all is specified, reconfigure all enlistments currently
registered with Scalar by the scalar.repo config key. Use this
option after each upgrade to get the latest features.
--maintenance=(enable|disable|keep)
By default, Scalar configures the enlistment to use Git’s
background maintenance feature; this is the same as using the
‘enable` value for this option. Use the disable value to
remove each considered enlistment from background maintenance.
Use `keep’ to leave the background maintenance configuration
untouched for these repositories.
Diagnose
diagnose [<enlistment>]
When reporting issues with Scalar, it is often helpful to
provide the information gathered by this command, including
logs and certain statistics describing the data shape of the
current enlistment.
The output of this command is a .zip file that is written into
a directory adjacent to the worktree in the src directory.
Delete
delete <enlistment>
This subcommand lets you delete an existing Scalar enlistment
from your local file system, unregistering the repository.
As part of both scalar clone and scalar register, certain Git
config values are set to optimize for large repositories or
cross-platform support. These options are updated in new Git
versions according to the best known advice for large
repositories, and users can get the latest recommendations by
running scalar reconfigure [--all].
This section lists justifications for the config values that are
set in the latest version.
am.keepCR=true
This setting is important for cross-platform development
across Windows and non-Windows platforms and keeping carriage
return (\r) characters in certain workflows.
commitGraph.changedPaths=true
This setting helps the background maintenance steps that
compute the serialized commit-graph to also store changed-path
Bloom filters. This accelerates file history commands and
allows users to automatically benefit without running a
foreground command.
commitGraph.generationVersion=1
While the preferred version is 2 for performance reasons,
existing users that had version 1 by default will need special
care in upgrading to version 2. This is likely to change in
the future as the upgrade story solidifies.
core.autoCRLF=false
This removes the transformation of worktree files to add CRLF
line endings when only LF line endings exist. This is removed
for performance reasons. Repositories that use tools that care
about CRLF line endings should commit the necessary files with
those line endings instead.
core.logAllRefUpdates=true
This enables the reflog on all branches. While this is a
performance cost for large repositories, it is frequently an
important data source for users to get out of bad situations
or to seek support from experts.
core.safeCRLF=false
Similar to core.autoCRLF=false, this disables checks around
whether the CRLF conversion is reversible. This is a
performance improvement, but can be dangerous if core.autoCRLF
is reenabled by the user.
credential.https://dev.azure.com.useHttpPath=true
This setting enables the credential.useHttpPath feature only
for web URLs for Azure DevOps. This is important for users
interacting with that service using multiple organizations and
thus multiple credential tokens.
feature.experimental=false
This disables the "experimental" optimizations grouped under
this feature config. The expectation is that all valuable
optimizations are also set explicitly by Scalar config, and
any differences are intentional. Notable differences include
several bitmap-related config options which are disabled for
client-focused Scalar repos.
feature.manyFiles=false
This disables the "many files" optimizations grouped under
this feature config. The expectation is that all valuable
optimizations are also set explicitly by Scalar config, and
any differences are intentional.
fetch.showForcedUpdates=false
This disables the check at the end of git fetch that notifies
the user if the ref update was a forced update (one where the
previous position is not reachable from the latest position).
This check can be very expensive in large repositories, so is
disabled and replaced with an advice message. Set
advice.fetchShowForcedUpdates=false to disable this advice
message.
fetch.unpackLimit=1
This setting prevents Git from unpacking packfiles into loose
objects as they are downloaded from the server. The default
limit of 100 was intended as a way to prevent performance
issues from too many packfiles, but Scalar uses background
maintenance to group packfiles and cover them with a
multi-pack-index, removing this issue.
fetch.writeCommitGraph=false
This config setting was created to help users automatically
update their commit-graph files as they perform fetches.
However, this takes time from foreground fetches and pulls and
Scalar uses background maintenance for this function instead.
gc.auto=0
This disables automatic garbage collection, since Scalar uses
background maintenance to keep the repository data in good
shape.
gui.GCWarning=false
Since Scalar disables garbage collection by setting gc.auto=0,
the git-gui tool may start to warn about this setting. Disable
this warning as Scalar’s background maintenance configuration
makes the warning irrelevant.
index.skipHash=true
Disable computing the hash of the index contents as it is
being written. This assists with performance, especially for
large index files.
index.threads=true
This tells Git to automatically detect how many threads it
should use when reading the index due to the default value of
core.preloadIndex, which enables parallel index reads. This
explicit setting also enables index.recordOffsetTable=true to
speed up parallel index reads.
index.version=4
This index version adds compression to the path names,
reducing the size of the index in a significant way for large
repos. This is an important performance boost.
log.excludeDecoration=refs/prefetch/*
Since Scalar enables background maintenance with the
incremental strategy, this setting avoids polluting git log
output with refs stored by the background prefetch operations.
merge.renames=true
When computing merges in large repos, it is particularly
important to detect renames to maximize the potential for a
result that will validate correctly. Users performing merges
locally are more likely to be doing so because a server-side
merge (via pull request or similar) resulted in conflicts.
While this is the default setting, it is set specifically to
override a potential change to diff.renames which a user may
set for performance reasons.
merge.stat=false
This disables a diff output after computing a merge. This
improves performance of git merge for large repos while
reducing noisy output.
pack.useBitmaps=false
This disables the use of .bitmap files attached to packfiles.
Bitmap files are optimized for server-side use, not
client-side use. Scalar disables this to avoid some
performance issues that can occur if a user accidentally
creates .bitmap files.
pack.usePathWalk=true
This enables the --path-walk option to git pack-objects by
default. This can accelerate the computation and compression
of packfiles created by git push and other repack operations.
receive.autoGC=false
Similar to gc.auto, this setting is disabled in preference of
background maintenance.
status.aheadBehind=false
This disables the ahead/behind calculation that would normally
happen during a git status command. This information is
frequently ignored by users but can be expensive to calculate
in large repos that receive thousands of commits per day. The
calculation is replaced with an advice message that can be
disabled by disabling the advice.statusAheadBehind config.
The following settings are different based on which platform is in
use:
core.untrackedCache=(true|false)
The untracked cache feature is important for performance
benefits on large repositories, but has demonstrated some bugs
on Windows filesystems. Thus, this is set for other platforms
but disabled on Windows.
http.sslBackend=schannel
On Windows, the openssl backend has some issues with certain
types of remote providers and certificate types. Override the
default setting to avoid these common problems.
git-clone(1), git-maintenance(1).
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2026-01-16. (At that time,
the date of the most recent commit that was found in the
repository was 2026-01-15.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Git 2.53.0.rc0 2026-01-15 SCALAR(1)
Pages that refer to this page: git(1)
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HTML rendering created 2026-01-16 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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