--- stage: Create group: Gitaly info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments type: reference, howto --- # Repository storage types **(CORE ONLY)** > - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/28283) in GitLab 10.0. > - Hashed storage became the default for new installations in GitLab 12.0 > - Hashed storage is enabled by default for new and renamed projects in GitLab 13.0. GitLab can be configured to use one or multiple repository storage paths/shard locations that can be: - Mounted to the local disk - Exposed as an NFS shared volume - Accessed via [Gitaly](gitaly/index.md) on its own machine. In GitLab, this is configured in `/etc/gitlab/gitlab.rb` by the `git_data_dirs({})` configuration hash. The storage layouts discussed here apply to any shard defined in it. The `default` repository shard that is available in any installations that haven't customized it, points to the local folder: `/var/opt/gitlab/git-data`. Anything discussed below is expected to be part of that folder. ## Hashed storage NOTE: In GitLab 13.0, hashed storage is enabled by default and the legacy storage is deprecated. Support for legacy storage is scheduled to be removed in GitLab 14.0. If you haven't migrated yet, check the [migration instructions](raketasks/storage.md#migrate-to-hashed-storage). The option to choose between hashed and legacy storage in the admin area has been disabled. Hashed storage is the storage behavior we rolled out with 10.0. Instead of coupling project URL and the folder structure where the repository is stored on disk, we are coupling a hash, based on the project's ID. This makes the folder structure immutable, and therefore eliminates any requirement to synchronize state from URLs to disk structure. This means that renaming a group, user, or project costs only the database transaction, and takes effect immediately. The hash also helps to spread the repositories more evenly on the disk, so the top-level directory contains fewer folders than the total number of top-level namespaces. The hash format is based on the hexadecimal representation of SHA256: `SHA256(project.id)`. The top-level folder uses the first 2 characters, followed by another folder with the next 2 characters. They are both stored in a special `@hashed` folder, to be able to co-exist with existing Legacy Storage projects: ```ruby # Project's repository: "@hashed/#{hash[0..1]}/#{hash[2..3]}/#{hash}.git" # Wiki's repository: "@hashed/#{hash[0..1]}/#{hash[2..3]}/#{hash}.wiki.git" ``` ### Translating hashed storage paths Troubleshooting problems with the Git repositories, adding hooks, and other tasks requires you translate between the human readable project name and the hashed storage path. #### From project name to hashed path The hashed path is shown on the project's page in the [admin area](../user/admin_area/index.md#administering-projects). To access the Projects page, go to **Admin Area > Overview > Projects** and then open up the page for the project. The "Gitaly relative path" is shown there, for example: ```plaintext "@hashed/b1/7e/b17ef6d19c7a5b1ee83b907c595526dcb1eb06db8227d650d5dda0a9f4ce8cd9.git" ``` This is the path under `/var/opt/gitlab/git-data/repositories/` on a default Omnibus installation. In a [Rails console](operations/rails_console.md#starting-a-rails-console-session), get this information using either the numeric project ID or the full path: ```ruby Project.find(16).disk_path Project.find_by_full_path('group/project').disk_path ``` #### From hashed path to project name To translate from a hashed storage path to a project name: 1. Start a [Rails console](operations/rails_console.md#starting-a-rails-console-session). 1. Run the following: ```ruby ProjectRepository.find_by(disk_path: '@hashed/b1/7e/b17ef6d19c7a5b1ee83b907c595526dcb1eb06db8227d650d5dda0a9f4ce8cd9').project ``` The quoted string in that command is the directory tree you can find on your GitLab server. For example, on a default Omnibus installation this would be `/var/opt/gitlab/git-data/repositories/@hashed/b1/7e/b17ef6d19c7a5b1ee83b907c595526dcb1eb06db8227d650d5dda0a9f4ce8cd9.git` with `.git` from the end of the directory name removed. The output includes the project ID and the project name: ```plaintext => # ``` ### Hashed object pools > [Introduced](https://gitlab.com/gitlab-org/gitaly/-/issues/1606) in GitLab 12.1. WARNING: Do not run `git prune` or `git gc` in pool repositories! This can cause data loss in "real" repositories that depend on the pool in question. Forks of public projects are deduplicated by creating a third repository, the object pool, containing the objects from the source project. Using `objects/info/alternates`, the source project and forks use the object pool for shared objects. Objects are moved from the source project to the object pool when housekeeping is run on the source project. ```ruby # object pool paths "@pools/#{hash[0..1]}/#{hash[2..3]}/#{hash}.git" ``` ### Hashed storage coverage migration Files stored in an S3-compatible endpoint do not have the downsides mentioned earlier, if they are not prefixed with `#{namespace}/#{project_name}`, which is true for CI Cache and LFS Objects. In the table below, you can find the coverage of the migration to the hashed storage. | Storable Object | Legacy storage | Hashed storage | S3 Compatible | GitLab Version | | --------------- | -------------- | -------------- | ------------- | -------------- | | Repository | Yes | Yes | - | 10.0 | | Attachments | Yes | Yes | - | 10.2 | | Avatars | Yes | No | - | - | | Pages | Yes | No | - | - | | Docker Registry | Yes | No | - | - | | CI Build Logs | No | No | - | - | | CI Artifacts | No | No | Yes | 9.4 / 10.6 | | CI Cache | No | No | Yes | - | | LFS Objects | Yes | Similar | Yes | 10.0 / 10.7 | | Repository pools| No | Yes | - | 11.6 | #### Avatars Each file is stored in a folder with its `id` from the database. The filename is always `avatar.png` for user avatars. When avatar is replaced, `Upload` model is destroyed and a new one takes place with different `id`. #### CI artifacts CI Artifacts are S3 compatible since **9.4** (GitLab Premium), and available in GitLab Core since **10.6**. #### LFS objects [LFS Objects in GitLab](../topics/git/lfs/index.md) implement a similar storage pattern using 2 chars, 2 level folders, following Git's own implementation: ```ruby "shared/lfs-objects/#{oid[0..1}/#{oid[2..3]}/#{oid[4..-1]}" # Based on object `oid`: `8909029eb962194cfb326259411b22ae3f4a814b5be4f80651735aeef9f3229c`, path will be: "shared/lfs-objects/89/09/029eb962194cfb326259411b22ae3f4a814b5be4f80651735aeef9f3229c" ``` LFS objects are also [S3 compatible](lfs/index.md#storing-lfs-objects-in-remote-object-storage). ## Legacy storage WARNING: In GitLab 13.0, hashed storage is enabled by default and the legacy storage is deprecated. If you haven't migrated yet, check the [migration instructions](raketasks/storage.md#migrate-to-hashed-storage). Support for legacy storage is scheduled to be removed in GitLab 14.0. If you're on GitLab 13.0 and later, switching new projects to legacy storage is not possible. The option to choose between hashed and legacy storage in the admin area has been disabled. Legacy storage is the storage behavior prior to version 10.0. For historical reasons, GitLab replicated the same mapping structure from the projects URLs: - Project's repository: `#{namespace}/#{project_name}.git` - Project's wiki: `#{namespace}/#{project_name}.wiki.git` This structure made it simple to migrate from existing solutions to GitLab and easy for Administrators to find where the repository is stored. On the other hand this has some drawbacks: Storage location concentrates a huge number of top-level namespaces. The impact can be reduced by the introduction of [multiple storage paths](repository_storage_paths.md). Because backups are a snapshot of the same URL mapping, if you try to recover a very old backup, you need to verify whether any project has taken the place of an old removed or renamed project sharing the same URL. This means that `mygroup/myproject` from your backup may not be the same original project that is at that same URL today. Any change in the URL needs to be reflected on disk (when groups / users or projects are renamed). This can add a lot of load in big installations, especially if using any type of network based filesystem.