Backups

One file matters. How to copy it safely while the thing is running.

operatorAssumes a terminal, Docker, and editing a config file.page 9 of 24

One file matters: queries.db. Everything else in the install directory can be rewritten from the wiki in two minutes.

incoming

queries.db-wal

0 transactions not yet in the .db

queries.db

everything up to the last checkpoint

cp queries.db backup.db → misses whatever is sitting in the -wal

Recent transactions live in the -wal file until a checkpoint folds them into the main database. A copy of queries.db on its own is therefore a database missing its most recent writes — it opens cleanly, which is what makes it dangerous. Use the .backup command, or stop the container first: a clean shutdown checkpoints everything.

Hot backup, container running#

SQLite’s own backup command takes a consistent snapshot while the database is being written to:

sudo docker exec elele-dns \
  sqlite3 /data/queries.db ".backup '/data/backup.db'"

sudo cp /opt/elele-dns/data/backup.db ~/elele-$(date +%F).db

Cold backup, container stopped#

cd /opt/elele-dns
sudo docker compose down
sudo cp data/queries.db ~/elele-$(date +%F).db
sudo docker compose up -d

A clean shutdown checkpoints the WAL into the main file, so after down the single .db is complete on its own.

Restoring#

cd /opt/elele-dns
sudo docker compose down
sudo cp ~/elele-2026-08-01.db data/queries.db
sudo rm -f data/queries.db-wal data/queries.db-shm
sudo docker compose up -d

Deleting the stale -wal and -shm alongside is the step people miss; leaving them next to a restored database is how you get a file that opens and then behaves strangely.

How big is it#

History	Rows	Roughly
7 days	~250k	60–90MB
30 days	~1M	150–250MB
90 days	~3M	300–500MB
Rollups only, per year	~500k	40–60MB, and it never gets pruned

Indexes are about a fifth of that. The store is deliberately index-heavy: it is the difference between a device page rendering in 40ms and in four seconds.

What is not worth backing up#

The vendored enrichment datasets. They are 45MB, they are re-downloadable, and they are rebuilt by npm run datasets:fetch.
.env, unless you would rather not retype three valuestwo values. It contains a password, so if you do keep a copy, keep it somewhere that deserves one.
AdGuard HomePi-hole’s own data directory, at least not for this product’s sake. Its log is the source, and everything read out of it is already in queries.db. Back it up for AdGuardPi-hole’s sake — your filter lists and client names live thereyour groups, adlists and local DNS records live there — on whatever schedule you already use for it.