2020-03-16 18:17:16 +00:00
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File systems
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~~~~~~~~~~~~
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2024-08-20 13:51:22 +00:00
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We recommend using a reliable, scalable journaling filesystem for the
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repository, e.g. zfs, btrfs, ext4, apfs.
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Borg now uses the ``borgstore`` package to implement the key/value store it
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uses for the repository.
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It currently uses the ``file:`` Store (posixfs backend) either with a local
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directory or via ssh and a remote ``borg serve`` agent using borgstore on the
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remote side.
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This means that it will store each chunk into a separate filesystem file
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(for more details, see the ``borgstore`` project).
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This has some pros and cons (compared to legacy borg 1.x's segment files):
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Pros:
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- Simplicity and better maintainability of the borg code.
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- Sometimes faster, less I/O, better scalability: e.g. borg compact can just
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remove unused chunks by deleting a single file and does not need to read
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and re-write segment files to free space.
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- In future, easier to adapt to other kinds of storage:
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borgstore's backends are quite simple to implement.
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2024-09-21 23:30:49 +00:00
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``sftp:`` and ``rclone:`` backends already exists, others might be easy to add.
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2024-08-20 13:51:22 +00:00
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- Parallel repository access with less locking is easier to implement.
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Cons:
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- The repository filesystem will have to deal with a big amount of files (there
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are provisions in borgstore against having too many files in a single directory
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by using a nested directory structure).
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- Bigger fs space usage overhead (will depend on allocation block size - modern
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filesystems like zfs are rather clever here using a variable block size).
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- Sometimes slower, due to less sequential / more random access operations.
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