Backing Up MongoDB using mongodump
Backing up your MongoDB data is critical to prevent data loss and ensure you can restore it in case of corruption, deletion, or system failure. MongoDB provides a built-in tool called mongodump
for this purpose.
What is mongodump?
mongodump
is a command-line tool that creates a binary export (BSON files) of your MongoDB databases. This backup can later be restored using mongorestore
.
Basic Syntax
mongodump --uri="mongodb://localhost:27017" --out=/path/to/backup
This command connects to your MongoDB instance running on localhost
and dumps all databases to the specified output directory.
Example 1: Backup All Databases
mongodump --out=./mongo-backup
This creates a folder named mongo-backup
in your current directory containing backups of all databases.
Output:
2025-05-01T09:00:00.123+0530 writing admin.system.version to 2025-05-01T09:00:00.456+0530 done dumping admin.system.version (1 document) 2025-05-01T09:00:00.789+0530 writing test.users to 2025-05-01T09:00:01.001+0530 done dumping test.users (3 documents)
Example 2: Backup a Specific Database
mongodump --db=test --out=./backup-testdb
This command only backs up the test
database into the backup-testdb
directory.
Question: Why might you back up only one database instead of all?
Answer: In large-scale applications, backing up just the relevant database (e.g., user data, logs) saves time, space, and processing power.
Example 3: Backup a Specific Collection
mongodump --db=test --collection=users --out=./backup-users
This command backs up only the users
collection from the test
database.
Output:
2025-05-01T09:10:22.001+0530 writing test.users to 2025-05-01T09:10:22.456+0530 done dumping test.users (3 documents)
Example 4: Backup with Authentication
mongodump --uri="mongodb://username:password@localhost:27017/test" --out=./auth-backup
If your MongoDB instance requires authentication, provide the URI with the correct username and password.
Understanding the Output Files
After running mongodump
, you’ll see the following structure:
./mongo-backup/ ├── admin │ └── system.version.bson ├── test │ └── users.bson └── metadata.json
Each .bson
file represents a dumped collection in binary format. These files are not human-readable but can be restored using mongorestore
.
Where is mongodump Installed?
mongodump
is part of the MongoDB Database Tools. If you installed MongoDB using official installers, it is likely already available in your terminal. If not, install it from: MongoDB Tools Download.
Common Use Cases
- Nightly or weekly automated backups
- Taking a snapshot before schema changes
- Exporting a database for staging or development
Summary
mongodump
is a simple yet powerful utility to export MongoDB databases, collections, or entire clusters to BSON files. It is the first step in any reliable MongoDB backup and disaster recovery plan.
In the next section, we’ll learn how to restore these backups using mongorestore
.