Export and Import MongoDB Data on Ubuntu 22.04

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Ubuntu MongoDB database operations backup

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2024-09-28

These notes cover moving a limited production-data sample into a development environment with MongoDB's command-line tools.

Protect production data

Export only data you are authorized to use. Remove or anonymize personal and secret values before moving a production sample into development, encrypt backup files at rest, and delete temporary copies when the test is complete.

Choose the correct tool

MongoDB separates logical data interchange from full-fidelity database backups:

Task	Export	Import or restore	Format
One collection for interchange	`mongoexport`	`mongoimport`	JSON, CSV, or TSV
Database or multiple collections	`mongodump`	`mongorestore`	BSON plus metadata

Use mongodump and mongorestore when indexes, BSON types, and collection metadata matter. JSON produced by mongoexport is not a replacement for a complete backup.

Install MongoDB Database Tools

The old apt-key and Ubuntu focal repository commands in the original 2024 note are no longer a good installation path for Ubuntu 22.04. Follow MongoDB's current Database Tools installation guide, download the .deb package matching the CPU architecture, and install that local file:

sudo apt install ./mongodb-database-tools-*.deb

Confirm the installed versions:

mongoexport --version
mongodump --version

The Database Tools release lifecycle is separate from the MongoDB Server release, so do not infer the tool version from a server package name.

Export data

Export one collection as JSON

mongoexport \
  --uri="mongodb://localhost:27017/mydatabase" \
  --collection=mycollection \
  --out=output.json

For newline-delimited JSON, each document is written as a separate JSON value. Read the current mongoexport documentation before selecting JSON-array or CSV options for another consumer.

Dump one database as BSON

mongodump \
  --uri="mongodb://localhost:27017/mydatabase" \
  --out=output

Dump every accessible database

mongodump \
  --uri="mongodb://localhost:27017" \
  --out=output

The account in the connection string must have permission to read every selected database.

Import or restore data

Import one JSON collection

mongoimport \
  --uri="mongodb://localhost:27017/mydatabase" \
  --collection=mycollection \
  --file=output.json

Restore one database

mongorestore \
  --uri="mongodb://localhost:27017" \
  --drop \
  --nsInclude='mydatabase.*' \
  output

Restore all databases in a dump directory

mongorestore \
  --uri="mongodb://localhost:27017" \
  --drop \
  output

--drop deletes destination collections

Before restoring each collection, mongorestore --drop removes the corresponding destination collection and its data. Point the URI at the intended environment, verify the dump, and take a separate backup before using it.

Common problems

`E11000 duplicate key error`

The destination already contains a document with a conflicting unique key. Choose the behavior intentionally:

import into an empty collection;
use --drop only when replacing that collection is safe;
use the documented mongoimport upsert options when a specific key should update existing records;
clean or remap conflicting data before import.

Do not add --drop merely to silence the error on an important database.

The destination database already exists

mongorestore merges into existing collections unless instructed otherwise. Use --drop for a controlled replacement, or restore to a different namespace and compare the data before switching applications.

Use mongoexport --query only to select documents for a JSON/CSV export. It does not make mongodump or mongorestore a filtered full backup.

`Authentication failed`

The user may have been created in admin while the application database appears in the path. Specify the authentication source in the URI:

mongoimport \
  --uri="mongodb://USERNAME:PASSWORD@localhost:27017/mydatabase?authSource=admin" \
  --collection=mycollection \
  --file=output.json

Avoid putting a real password in shell history or process listings. Prefer an approved secret mechanism or an interactive password option supported by the current tool. Also verify the username, roles, authentication mechanism, TLS requirements, and target host; an authentication error is not explained solely by the MongoDB server being newer than version 4.0.

Verification

After an import or restore:

compare expected collection and document counts;
verify indexes and validation rules when using a BSON restore;
run application-level reads against the development copy;
inspect the tool output for skipped documents and errors;
remove the exported production sample when it is no longer required.