Back Up and Restore with MongoDB Tools
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This tutorial describes the process for creating backups and restoring data using the utilities provided with MongoDB. The mongodump and mongorestore utilities work with BSON data dumps, and are useful for creating backups of small deployments. For resilient and non-disruptive backups, use a file system or block-level disk snapshot function, such as the methods described in the MongoDB Backup Methods document.
Because mongodump and mongorestore operate by interacting with a running mongod instance, they can impact the performance of your running database. Not only do the tools create traffic for a running database instance, they also force the database to read all data through memory. When MongoDB reads infrequently used data, it can evict more frequently accessed data, causing a deterioration in performance for the database’s regular workload.
When backing up your data with MongoDB’s tools, consider the following guidelines:
- Label files so that you can identify the contents of the backup as well as the point in time that the backup reflects.
- Use an alternative backup strategy such as Filesystem Snapshots or MongoDB Cloud Manager if the performance impact of
mongodumpandmongorestoreis unacceptable for your use case. - Use
--oplogto capture incoming write operations during themongodumpoperation to ensure that the backups reflect a consistent data state. - Ensure that your backups are usable by restoring them to a test MongoDB deployment.
See also
MongoDB Backup Methods and MongoDB Cloud Manager Backup documentation for more information on backing up MongoDB instances. Additionally, consider the following reference documentation for the MongoDB import/export tools:
Binary BSON Dumps
The mongorestore and mongodump utilities work with BSON data dumps, and are useful for creating backups of small deployments. For resilient and non-disruptive backups, use a file system or block-level disk snapshot function, such as the methods described in the MongoDB Backup Methods document.
Use these tools for backups if other backup methods, such as MongoDB Cloud Manager or file system snapshots are unavailable.
Procedures
Back Up a Database with mongodump
Exclude local Database
mongodump excludes the content of the local database in its output.
Required Access
To run mongodump against a MongoDB deployment that has access control enabled, you must have privileges that grant find action for each database to back up. The built-in backup role provides the required privileges to perform backup of any and all databases.
Changed in version 3.2.1: The backup role provides additional privileges to back up the system.profile collections that exist when running with database profiling. Previously, users required an additional read access on this collection.
Basic mongodump Operations
The mongodump utility backs up data by connecting to a running mongod or mongos instance.
The utility can create a backup for an entire server, database or collection, or can use a query to backup just part of a collection.
When you run mongodump without any arguments, the command connects to the MongoDB instance on the local system (e.g. 127.0.0.1 or localhost) on port 27017 and creates a database backup named dump/ in the current directory.
To backup data from a mongod or mongos instance running on the same machine and on the default port of 27017, use the following command:
The data format used by mongodump from version 2.2 or later is incompatible with earlier versions of mongod. Do not use recent versions of mongodump to back up older data stores.
You can also specify the --host and --port of the MongoDB instance that the mongodump should connect to. For example:
mongodump will write BSON files that hold a copy of data accessible via the mongod listening on port 27017 of the mongodb.example.net host. See Create Backups from Non-Local mongod Instances for more information.
To specify a different output directory, you can use the --out or -o option:
To limit the amount of data included in the database dump, you can specify --db and --collection as options to mongodump. For example:
This operation creates a dump of the collection named myCollection from the database test in a dump/ subdirectory of the current working directory.
mongodump overwrites output files if they exist in the backup data folder. Before running the mongodump command multiple times, either ensure that you no longer need the files in the output folder (the default is the dump/ folder) or rename the folders or files.
Point in Time Operation Using Oplogs
Use the --oplog option with mongodump to collect the oplog entries to build a point-in-time snapshot of a database within a replica set. With --oplog, mongodump copies all the data from the source database as well as all of the oplog entries from the beginning to the end of the backup procedure. This operation, in conjunction with mongorestore --oplogReplay, allows you to restore a backup that reflects the specific moment in time that corresponds to when mongodump completed creating the dump file.
Restore a Database with mongorestore
Access Control
To restore data to a MongoDB deployment that has access control enabled, the restore role provides the necessary privileges to restore data from backups if the data does not include system.profile collection data and you run mongorestore without the --oplogReplay option.
If the backup data includes system.profile collection data or you run with --oplogReplay, you need additional privileges:
system.profile |
If the backup data includes |