How to Use mongodump for MongoDB Backups

Use mongodump to create a binary backup of your MongoDB database by running it from the command line. You can specify the database, collection, or output directory with options like --db, --collection, and --out.

Syntax

The basic syntax of mongodump is:

• mongodump [options]

Key options include:

• --db <database>: Specify which database to dump.
• --collection <collection>: Dump only a specific collection.
• --out <directory>: Directory where dump files are saved.
• --uri <connection-string>: MongoDB connection string to connect to a remote or local server.

bash

mongodump --db mydatabase --collection mycollection --out ./backup

Example

This example shows how to dump the entire testdb database into a folder named dump in the current directory.

bash

mongodump --db testdb --out ./dump

Output

2024-06-01T12:00:00.000+0000	writing testdb.users to dump/testdb/users.bson
2024-06-01T12:00:00.100+0000	writing testdb.orders to dump/testdb/orders.bson
Dump completed successfully.

Common Pitfalls

Common mistakes when using mongodump include:

• Not specifying the --db option and dumping all databases unintentionally.
• Forgetting to set the correct --uri for remote servers, causing connection failures.
• Using a directory for --out that does not have write permissions.
• Expecting mongodump to export data in JSON format; it exports in BSON format.

bash

mongodump --db testdb --out /root/backup
# Error: permission denied

mongodump --db testdb --out ./backup
# Correct usage with writable directory

Quick Reference

Option	Description
--db	Dump only the specified database
--collection	Dump only the specified collection
--out	Directory to save the dump files
--uri	MongoDB connection string for remote or local server
--gzip	Compress the dump files using gzip
--archive=	Create a single archive file instead of a folder

Key Takeaways

Use mongodump to create binary backups of MongoDB databases or collections.

Specify the database with --db and output folder with --out for targeted backups.

mongodump exports data in BSON format, not JSON.

Ensure you have write permissions on the output directory to avoid errors.

Use --uri to connect to remote MongoDB instances securely.