Git-annex supports several levels of trust of a repository:

  • semitrusted (default)
  • untrusted
  • trusted
  • dead

semitrusted

Normally, git-annex does not fully trust its stored location tracking information. When removing content, it will directly check that other repositories have enough copies.

Generally that explicit checking is a good idea. Consider that the current location tracking information for a remote may not yet have propagated out. Or, a remote may have suffered a catastrophic loss of data, or itself been lost.

There is still some trust involved here. A semitrusted repository is depended on to retain a copy of the file content; possibly the only copy.

(Being semitrusted is the default. The git-annex semitrust command restores a repository to this default, when it has been overridden. The --semitrust option can temporarily restore a repository to this default.)

untrusted

An untrusted repository is not trusted to retain data at all. Git-annex will retain sufficient copies of data elsewhere.

This is a good choice for eg, portable drives that could get lost. Or, if a disk is known to be dying, you can set it to untrusted and let git annex fsck warn about data that needs to be copied off it.

To configure a repository as untrusted, use the git-annex untrust command.

trusted

Sometimes, you may have reasons to fully trust the location tracking information for a repository. For example, it may be an offline archival drive, from which you rarely or never remove content. Deciding when it makes sense to trust the tracking info is up to you.

To configure a repository as fully and permanently trusted, use the git-annex-trust command.

Note that after dropping content from a trusted repo, other repos that are out of sync and trust it to still contain the content can drop copies, even though that will violate ?numcopies. So using trusted repositories can lead to data loss. It is best to take extreme care when dropping content from trusted repositories, the same as if you were using --force.

dead

This is used to indicate that you have no trust that the repository exists at all. It's appropriate to use when a drive has been lost, or a directory irretrievably deleted. It will make git-annex avoid even showing the repository as a place where data might still reside.

To configure a repository as dead and lost, use the git-annex-dead command.