📁 Runtime directory

New in version 1.9.0 borgmatic uses a runtime directory for temporary file storage, such as for streaming database dumps to Borg, creating filesystem snapshots, saving bootstrap metadata, and so on. To determine the path for this runtime directory, borgmatic probes the following values:

1. The user_runtime_directory borgmatic configuration option.
2. The XDG_RUNTIME_DIR environment variable, usually /run/user/$UID (where $UID is the current user's ID), automatically set by PAM on Linux for a user with a session.
3. New in version 1.9.2The RUNTIME_DIRECTORY environment variable, set by systemd if RuntimeDirectory=borgmatic is added to borgmatic's systemd service file.
4. New in version 1.9.1The TMPDIR environment variable, set on macOS for a user with a session, among other operating systems.
5. New in version 1.9.1The TEMP environment variable, set on various systems.
6. New in version 1.9.2 Hard-coded /tmp. Prior to version 1.9.2This was instead hard-coded to /run/user/$UID.

You can see the runtime directory path that borgmatic selects by running with --verbosity 2 and looking for Using runtime directory in the output.

Regardless of the runtime directory selected, borgmatic stores its files within a borgmatic subdirectory of the runtime directory. Additionally, in the case of TMPDIR, TEMP, and the hard-coded /tmp, borgmatic creates a randomly named subdirectory in an effort to reduce path collisions in shared system temporary directories.

Prior to version 1.9.0 borgmatic created temporary streaming database dumps within the ~/.borgmatic directory by default. At that time, the path was configurable by the borgmatic_source_directory configuration option (now deprecated).