Copies
What a copy is, and the three modes
A copy is another place that Keepfin keeps up to date with your Keepfin folder, or with part of it. You choose how it behaves.
What a copy is#
A copy can be an external drive, a second disk, a network share, a memory card, a USB stick for the car, or a folder in a cloud account (see Cloud accounts). It can also be a folder on another device of yours (see A copy on another device).
Your Keepfin folder stays the main place. A cloud account or a drive is always a copy, never the main folder, so Keepfin keeps working with no internet and catches up later.
The three modes#
Every copy has one mode, always shown in words on its card. The mode is chosen when you add the copy and cannot be changed afterwards; add another copy if you want a different mode.
| Mode | What happens | When something is removed | Good for |
|---|---|---|---|
| Backup | New and changed things are copied to the backup. A file that changes is kept as an earlier version, so an edit or a bad tag change can be undone. | Kept on the backup until you press Clean up. | An external backup drive. |
| Two-way | Add or change things on either side and the other side follows: files, playlists and history. If both sides change, both versions are kept. | Travels both ways. Deleted files wait 30 days in Keepfin's trash first. | A second computer, a drive shared between computers, a cloud folder. |
| Mirror | The copy always matches what you chose to keep. | Goes to the copy's trash and is deleted for good after 30 days. | The USB stick in the car. |
A full copy is a library of its own#
A copy that keeps everything is a complete Keepfin folder. Plug the drive into any computer, point Keepfin at it with I already have a Keepfin folder on the first start, and everything is there.
Every copy knows your whole library#
Even a copy that keeps only some files knows what exists elsewhere. That lets other places say "On Hisham's PC" for a song they do not hold. Taking a playlist off a copy never deletes its songs anywhere. Deleting a song from your library is a separate, confirmed action.
Safety built in#
- Preview first. Adding a copy shows what the first sync would do, such as "Will copy 1,240 files (8.2 GB)". The first sync only adds files.
- A guard on large changes. A sync that would remove or replace a large share of a copy waits for your OK (Needs your OK).
- Free space is checked before it starts.
- Checked copying. Every file is checked after it is copied. An interrupted sync continues where it stopped.
- Nothing is overwritten silently. Differences are kept, not guessed (see Needs review).
How it works#
How it works
Keepfin compares an inventory of both sides with what the library says should be there. Each copy action is written to a journal first, then the file is copied to a temporary name, checked against its expected fingerprint, and only then put in place. If the sync is interrupted, Keepfin reads the journal and finishes or undoes the step. It never decides to delete just because a file looks absent: a list that might be incomplete never causes a removal.