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add

Track data files or directories with DVC.

Synopsis

usage: dvc add [-h] [-q | -v] [-f] [--no-commit]
               [--glob] [-o <path>]
               [--to-remote] [-r <name>] [--remote-jobs <number>]
               targets [targets ...]
positional arguments:
  targets               Files or directories to add or update

Description

DVC allows tracking datasets using .dvc files as lightweight pointers to your data. The dvc add command is used to track and update your data by creating or updating .dvc files.

With dvc add, you can seamlessly track datasets, models or large files by specifying the targets you want to track. DVC manages the corresponding .dvc files, ensuring the consistency of your data to your workspace.

The targets can be individual files, directories, or specific paths within an already tracked dataset. For new files and directories that are not currently tracked, DVC creates new .dvc files to track the added data, and stores them in the cache.

If the target is a part of an existing dataset, only that portion of the dataset is updated, and associated .dvc file is updated to reflect the changes. If the target path does not exist in workspace but was previously tracked, it will be removed from the dataset, and the .dvc file will be updated accordingly.

Leveraging the metadata in .dvc files and the cache structure, datasets don't need to exist completely in your workspace to update. You can pull a dataset partially and operate on it. DVC will automatically update the relevant .dvc file to reflect the changes. This capability allows you to work with large datasets without having to download the entire dataset to your local machine.

This command can be used to track large files, models, dataset directories, etc. that are too big for Git to handle directly. This enables versioning them indirectly with Git.

See also dvc.yaml and dvc stage add for more advanced ways to track and version intermediate and final results (like ML models).

The command will add the targets to .gitignore to prevent them from being committed to the Git repository (unless dvc init --no-scm was used when initializing the DVC project). The generated .dvc files can be staged automatically if core.autostage is set.

To exclude specific files or directories from being added, you can add corresponding patterns to a .dvcignore file.

You can also undo dvc add to stop tracking files or directories.

By default, DVC tries to use reflinks (see File link types) to avoid copying any file contents and to optimize .dvc file operations for large files. DVC also supports other link types for use on file systems without reflink support, but they have to be specified manually. Refer to the cache.type config option in dvc config cache for more information.

Adding entire directories

A dvc add target can be either a file or a directory. In the latter case, a .dvc file is created for the top of the hierarchy (with default name <dir_name>.dvc).

Every file in the dir is cached normally (unless the --no-commit option is used), but DVC does not produce individual .dvc files for each one. Instead, the single .dvc file references a special JSON file in the cache (with .dir extension), that in turn points to the added files.

Refer to Structure of cache directory for more info. on .dir cache entries.

Note that DVC commands that use tracked data support granular targeting of files and directories, even when contained in a parent directory added as a whole. Examples: dvc push, dvc pull, dvc get, dvc import, etc.

To avoid adding files inside a directory accidentally, you can add the corresponding patterns to .dvcignore.

dvc add supports symlinked files as targets. But if a target path is a directory symlink, or if it contains any intermediate directory symlinks, it cannot be added to DVC.

For example, given the following project structure:

.
├── .dvc
├── dir
│   └── file
├── link_to_dir -> dir
├── link_to_external_dir -> /path/to/dir
├── link_to_external_file -> /path/to/file
└── link_to_file -> dir/file

link_to_file and link_to_external_file are both valid symlink targets to dvc add. But link_to_dir, link_to_external_dir, and link_to_dir/file are not.

Options

  • --no-commit - do not store targets in the cache (the .dvc file is still created). Use dvc commit to finish the operation (similar to git commit after git add).

  • --glob - allows adding files and directories that match the pattern specified in targets. Shell style wildcards supported: *, ?, [seq], [!seq], and **

  • -o <path>, --out <path> - specify a path to the desired location in the workspace to place the targets (copying them from their current location). This enables targeting data outside the project.

  • --to-remote - add a target that's outside the project, neither move it into the workspace, nor cache it. Transfer it directly to remote storage instead (the default one unless otherwise specified with -r). Implies --out .. Use dvc pull to get the data locally.

  • -r <name>, --remote <name> - name of the dvc remote to transfer external target to (can only be used with --to-remote).

  • --remote-jobs <number> - parallelism level for DVC to transfer data when using --to-remote. The default value is 4 \* cpu_count(). For SSH remotes, the default is 4. Using more jobs may speed up the operation.

  • -f, --force - when using --out to specify a local target file or directory, the operation will fail if those paths already exist. this flag will force the operation causing local files/dirs to be overwritten by the command.

  • -h, --help - prints the usage/help message, and exit.

  • -q, --quiet - do not write anything to standard output. Exit with 0 if no problems arise, otherwise 1.

  • -v, --verbose - displays detailed tracing information.

Example: Single file

Track a file with DVC:

$ dvc add data.xml

As indicated above, a .dvc file has been created for data.xml. Let's explore the result:

$ tree
.
├── data.xml
└── data.xml.dvc

Let's check the data.xml.dvc file inside:

outs:
  - md5: 6137cde4893c59f76f005a8123d8e8e6
    path: data.xml

This is a standard .dvc file with only one output (outs field). The hash value (md5 field) corresponds to a file path in the cache.

$ file .dvc/cache/files/md5/d8/acabbfd4ee51c95da5d7628c7ef74b
.dvc/cache/files/md5/61/37cde4893c59f76f005a8123d8e8e6: ASCII text

⚠️ Tracking compressed files (e.g. ZIP or TAR archives) is not recommended, as dvc add supports tracking directories (details below).

Example: Directory

Let's suppose your goal is to build an algorithm to identify cats and dogs in pictures. You may then have hundreds or thousands of pictures of these animals in a directory, and this is your training dataset:

$ tree pics --filelimit 3
pics
├── train
│   ├── cats [many image files]
│   └── dogs [many image files]
└── validation
    ├── cats [more image files]
    └── dogs [more image files]

Tracking a directory with DVC as simple as with a single file:

$ dvc add pics

There are no .dvc files generated within this directory structure to match each image, but the image files are all cached. A single pics.dvc file is generated for the top-level directory, and it contains:

outs:
  - md5: ce57450aa92ab8f2b957c24b0df73edc.dir
    path: pics

Refer to Adding entire directories for more info.

This allows us to treat the entire directory structure as a single data artifact. For example, you can pass it as a dependency to a stage definition:

$ dvc stage add -n train \
                -d train.py -d pics \
                -M metrics.json -o model.h5 \
                python train.py

To try this example, see the versioning tutorial.

Example .dvcignore

Let's take an example to illustrate how .dvcignore interacts with dvc add.

$ mkdir dir
$ echo file_one > dir/file1
$ echo file_two > dir/file2

Now add file1 to .dvcignore and track the entire dir directory with dvc add.

$ echo dir/file1 > .dvcignore
$ dvc add dir

Let's now modify file1 (which is listed in .dvcignore) and run dvc status:

$ echo file_one_changed > dir/file1
$ dvc status
Data and pipelines are up to date.

dvc status ignores changes to files listed in .dvcignore.

Let's have a look at cache directory:

$ tree .dvc/cache/files/md5
.dvc/cache/files/md5
├── 0a
│   └── ec3a687bd65c3e6a13e3cf20f3a6b2.dir
└── 52
    └── 4bcc8502a70ac49bf441db350eafc2

Only the hash values of the dir/ directory (with .dir file extension) and file2 have been cached.

Example: Transfer to remote storage

Sometimes there's not enough space in the local environment to import a large dataset, but you still want to track it in the project so that dvc pull can download it later.

As long as you have setup a dvc remote that can handle the data, this can be achieved with the --to-remote flag. It creates a .dvc file without downloading anything, transferring a target directly to remote storage instead.

Let's add a data.xml file via HTTP straight "to remote":

$ dvc add https://data.dvc.org/get-started/data.xml --to-remote
...
$ ls
data.xml.dvc

Since a .dvc file is created in the workspace, whenever anyone wants to actually download the data they can use dvc pull:

$ dvc pull data.xml.dvc
A       data.xml
1 file added

Note that you can also do this with dvc import-url. This has the added benefit of keeping a connection to the data source so it can be updated later (with dvc update).

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