35 lines
1.8 KiB
Markdown
35 lines
1.8 KiB
Markdown
Annexed data is stored inside your git repository's `.git/annex` directory.
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Some [[special_remotes]] can store annexed data elsewhere.
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It's important that data not get lost by an ill-considered `git annex drop`
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command. So, git-annex can be configured to try
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to keep N copies of a file's content available across all repositories.
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(Although [[untrusted_repositories|trust]] don't count toward this total.)
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By default, N is 1; it is configured by running `git annex numcopies N`.
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This default can be overridden on a per-file-type basis by the annex.numcopies
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setting in `.gitattributes` files. The --numcopies switch allows
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temporarily using a different value.
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`git annex drop` attempts to check with other git remotes, to check that N
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copies of the file exist. If enough repositories cannot be verified to have
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it, it will retain the file content to avoid data loss. Note that
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[[trusted_repositories|trust]] are not explicitly checked.
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For example, consider three repositories: Server, Laptop, and USB. Both Server
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and USB have a copy of a file, and N=1. If on Laptop, you `git annex get
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$file`, this will transfer it from either Server or USB (depending on which
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is available), and there are now 3 copies of the file.
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Suppose you want to free up space on Laptop again, and you `git annex drop` the file
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there. If USB is connected, or Server can be contacted, git-annex can check
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that it still has a copy of the file, and the content is removed from
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Laptop. But if USB is currently disconnected, and Server also cannot be
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contacted, it can't verify that it is safe to drop the file, and will
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refuse to do so.
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With N=2, in order to drop the file content from Laptop, it would need access
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to both USB and Server.
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For more complicated requirements about which repositories contain which
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content, see [[required_content]].
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