Data folder and backups
What lives in the data folder, what you can safely delete, and how to back it up.
Everything Parallax remembers lives in the data folder you mounted at /app/data when you installed it. Your media is never copied in there. This page explains what is inside, so you know what to back up and what is safe to throw away.
What is in it
| Item | What it is | Can it be rebuilt? |
|---|---|---|
transcoder.db (plus -wal and -shm files) | The database: your libraries, the list of files and their details, settings, job history, download history and statistics. | No. This is the one that matters. |
thumbnails/ | Video thumbnails. | Yes, they are made again when you look at the files. |
image-thumbnails/ | Picture thumbnails. | Yes. |
organize-thumbnails/ | Thumbnails for the Organize page. Old ones are cleared out automatically. | Yes. |
models/ | Downloaded detection models, such as the larger content detection model. | Yes, from Settings → AI Models. |
stream-cache/ | The playback cache, described on Playback and audio conversion. | Yes. It is wiped every time Parallax starts. |
| Download tool files | The download tool and its helper, which Settings → Downloads installs. | Yes, install them again. |
alass | The subtitle sync tool. | Yes. |
| A Galleries folder | Saved gallery link lists, the "already downloaded" archive and any tool updates. | The lists and archive cannot. The rest can. |
Backing up
The database is the only thing you really need. If you copy the whole data folder you get everything, which is the simplest option.
- Stop Parallax:
docker compose down. - Copy the
datafolder somewhere safe. - Start it again:
docker compose up -d.
Stop it first, because the database is in the middle of being written to while Parallax runs, and a copy taken then can be inconsistent. The database also uses extra -wal and -shm files next to it, and all three need to be copied together.
To go back, stop Parallax, put the backup in place of data, and start it again.
Moving Parallax to a new machine works the same way: copy the folder across, mount it at /app/data and start. If your media is mounted at the same path inside the container, everything will be exactly where it was.
Making space
If the data folder has grown big, the safe things to delete are the thumbnail folders and stream-cache, with Parallax stopped. They will be made again when needed, so the only cost is a short wait the next time you browse.
To start completely fresh without touching your files, use Purge all library data in Settings → General rather than deleting things by hand. See Settings.
Permissions
The folder has to be writable by the user you run the container as (the user: line in your compose file). If it is not, Parallax cannot start properly. See Troubleshooting.