Annexed data is stored inside  your git repository's `.git/annex` directory.
Some [[special_remotes]] can store annexed data elsewhere.

It's important that data not get lost by an ill-considered `git-annex drop`
command.  So, git-annex can be configured to try to keep a number of copies
of a file's content available across all repositories. 

By default, it keeps 1 copy; this is configured by running `git-annex
numcopies N`, or can be overridden on a per-file-type basis by the
annex.numcopies setting in `.gitattributes` files. The --numcopies switch
allows temporarily using a different value.

When dropping content, git-annex checks with remotes to make sure If enough
other repositories cannot be verified to have copies, it will refuse to
drop it, avoid data loss.

In unusual situations, involving special remotes that do not support
locking, and concurrent drops of the same content from multiple
repositories, git-annex may violate the numcopies setting. It still
guarantees at least 1 copy is preserved. This can be configured by
running `git-annex mincopies N` or can be overridden on a per-file-type
basis by the annex.mincopies setting in `.gitattributes` files. 
The --mincopies switch allows temporarily using a different value.

Note that [trusted repositories|trust]] are assumed to
continue to contain content, so checking them is skipped. So dropping
content from trusted repositories does risk numcopies and mincopies 
later being violated.

To express more detailed requirements about which repositories contain which
content, see [[required_content]].

## example

For example, consider three repositories: Server, Laptop, and USB. Both
Server and USB have a copy of a file, and numcopies is 1. If on Laptop, you
`git-annex get $file`, this will transfer it from either Server or USB
(depending on which is available), and there are now 3 copies of the file.

Suppose you want to free up space on Laptop again, and you `git-annex drop`
the file there. If USB is connected, or Server can be contacted, git-annex
can check that it still has a copy of the file, and the content is removed
from Laptop. But if USB is currently disconnected, and Server also cannot
be contacted, it can't verify that it is safe to drop the file, and will
refuse to do so.

With numcopies of 2, in order to drop the file content from Laptop, it
would need access to both USB and Server.
