Migrate into MongoDB

Tested with: MongoDB (Percona Server) 8.0 on Databasezy · zb CLI 0.1

Sources: MongoDB Atlas, Railway, DigitalOcean, self-hosted MongoDB or FerretDB, Docker containers, mongodump archives (.bson.tar), another Databasezy instance.

How the copy works

mongodump --archive | mongorestore --archive, streamed with no intermediate file. --include maps to --nsInclude, and a different target database name is mapped with --nsFrom/--nsTo. Uploaded .bson.tar files are unpacked and restored with mongorestore --dir.

FerretDB and MongoDB speak the same wire protocol, so MongoDB to FerretDB and FerretDB to MongoDB use the same path; FerretDB reports index options it does not support.

Run it

# --dry-run prints the preflight checklist and the exact plan without changing anything
zb migrate --from "mongodb+srv://migrator:[email protected]/app" --engine mongodb --to inst_abc
zb migrate --from ./app.bson.tar --engine mongodb --to inst_abc
zb migrate --from local --engine mongodb --db app --to inst_abc   # mongodump --archive locally

Follow it with zb migrate status <mig_id>, or in the portal under the instance’s Migrate in tab.

What is verified

Document count per collection and the total index count. Mismatches are listed in the result; nothing is switched for you.

Not carried over

Copy only; change-stream sync is not offered.
Atlas Search indexes, triggers and Data API settings are Atlas features and are not copied.
Users and roles are not copied.

How migrations work covers preflight, verification and cutover; engine conversions covers moves between engines.