Runtime flags

Channel Vault NAS is configured with CVN_* environment variables. Set them in .env, .env.runtime, your Compose file, or the process environment.

Common flags

CVN_DOWNLOAD_DIR=./downfolder
CVN_DATABASE_URL=sqlite+aiosqlite:///./metadata/app.db
CVN_DB_MIGRATE_ON_STARTUP=true
CVN_DOWNLOAD_WORKER_ENABLED=false
CVN_DOWNLOAD_WORKER_SCHEDULER_ENABLED=false
CVN_DOWNLOAD_WORKER_SCHEDULER_INTERVAL_SECONDS=300
CVN_DOWNLOAD_WORKER_SCHEDULER_LIMIT=5
CVN_METADATA_SYNC_SCHEDULER_ENABLED=false
CVN_METADATA_SYNC_SCHEDULER_INTERVAL_SECONDS=900
CVN_METADATA_SYNC_SCHEDULER_LIMIT=2
CVN_CHANNEL_PROBE_VIDEO_LIMIT=500
CVN_PRESERVATION_CONFIRM_HOURS=24
CVN_YTDLP_BINARY=yt-dlp
CVN_FFPROBE_BINARY=ffprobe

What they do

Flag	Purpose
CVN_DOWNLOAD_DIR	Archive root. Media is written under here (see Filesystem contract).
CVN_DATABASE_URL	SQLAlchemy URL for the metadata index (SQLite by default).
CVN_DB_MIGRATE_ON_STARTUP	Run schema migrations on boot.
CVN_DOWNLOAD_WORKER_ENABLED	Master switch for real transfers. false = safe by default.
CVN_DOWNLOAD_WORKER_SCHEDULER_ENABLED	Let the scheduler auto-claim download jobs.
CVN_DOWNLOAD_WORKER_SCHEDULER_INTERVAL_SECONDS	How often the download scheduler ticks.
CVN_DOWNLOAD_WORKER_SCHEDULER_LIMIT	Max jobs claimed per scheduler tick.
CVN_METADATA_SYNC_SCHEDULER_ENABLED	Let the scheduler auto-sync channel metadata.
CVN_METADATA_SYNC_SCHEDULER_INTERVAL_SECONDS	How often the metadata scheduler ticks.
CVN_METADATA_SYNC_SCHEDULER_LIMIT	Max channels synced per tick.
CVN_CHANNEL_PROBE_VIDEO_LIMIT	Maximum uploads returned by a channel probe (default 500).
CVN_PRESERVATION_CONFIRM_HOURS	Age of the last recorded source sighting before an absent upload can be marked removed (default 24 hours).
CVN_YTDLP_BINARY	Path/name of the yt-dlp binary.
CVN_FFPROBE_BINARY	Path/name of the ffprobe binary.

Turn on downloads deliberately

Start automatic backup and the Settings controls apply worker/scheduler changes immediately. Environment edits outside the UI need a process restart; changes to Compose .env values require container recreation, not just docker compose restart. See Enable real downloads.

Preservation Watch limits

A sync compares known videos with the returned channel listing, not with every video's watch page. Empty results are ignored. For a truncated listing, older videos outside the covered upload-date window are left unchanged.

The confirmation threshold is measured from last_seen_in_source_at (falling back to discovery/creation time), not from the first sync that reports an absence. A video last seen more than 24 hours ago can therefore be marked removed on its first absent sync. This is not evidence of continuous absence, a specific removal reason, or the absence of copies elsewhere. Preserved means the source is marked absent and the app has a local archived-media record; use storage checks to verify the files. Reappearance resets the source state to available.

Process and recovery model

Run one API process and one replica per metadata database. Do not start multiple Uvicorn workers or API containers against the same database. Schedulers, child-process ownership, and WebSocket delivery are process-local.

On shutdown, active downloads are terminated and marked failed. On startup, stale running jobs, worker runs, and download scheduler ticks are marked failed so they cannot stay stuck indefinitely. Partial files remain in place; explicitly retry the job to let yt-dlp --continue attempt to resume it. Resume depends on the source and file format and is not guaranteed.

Access flags

Flag	Purpose
CVN_AUTH_TOKEN	Require a bearer / X-CVN-Token for API and unlock the console. See Access token.

Restart adapters

Restart adapter flags are documented in the Settings tab. Supported adapter families in the backend are:

• Manual / local dev
• Docker Compose guidance
• systemd
• supervisor
• Synology package
• QNAP package
• an explicit supervised restart hook

These let the Settings → Runtime env manifest drawer emit the exact restart command for your platform after you change a non-secret runtime override.