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Back Up and Restore with MongoDB Tools¶
This document describes the process for writing and restoring backups to files in binary format with the mongodump and mongorestore tools.
Use these tools for backups if other backup methods, such as the MMS Backup Service or file system snapshots are unavailable.
See also
Backup a Database with mongodump¶
mongodump does not dump the content of the local database.
To backup all the databases in a cluster via mongodump, you should have the backup role. The backup role provides the required privileges for backing up all databases. The role confers no additional access, in keeping with the policy of least privilege.
To backup a given database, you must have read access on the database. Several roles provide this access, including the backup role.
To backup the system.profile collection, which is created when you activate database profiling, you must have additional read access on this collection. Several roles provide this access, including the clusterAdmin and dbAdmin roles.
Changed in version 2.6.
To backup users and user-defined roles for a given database, you must have access to the admin database. MongoDB stores the user data and role definitions for all databases in the admin database.
Specifically, to backup a given database’s users, you must have the find action on the admin database’s admin.system.users collection. The backup and userAdminAnyDatabase roles both provide this privilege.
To backup the user-defined roles on a database, you must have the find action on the admin database’s admin.system.roles collection. Both the backup and userAdminAnyDatabase roles provide this privilege.
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:
mongodump
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 --host mongodb.example.net --port 27017
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:
mongodump --out /data/backup/
To limit the amount of data included in the database dump, you can specify --db and --collection as options to mongodump. For example:
mongodump --collection myCollection --db test
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.
Create Backups from Non-Local mongod Instances¶
The --host and --port options for mongodump allow you to connect to and backup from a remote host. Consider the following example:
mongodump --host mongodb1.example.net --port 3017 --username user --password pass --out /opt/backup/mongodump-2013-10-24
On any mongodump command you may, as above, specify username and password credentials to specify database authentication.
Restore a Database with mongorestore¶
Changed in version 2.6.
To restore users and user-defined roles on a given database, you must have access to the admin database. MongoDB stores the user data and role definitions for all databases in the admin database.
Specifically, to restore users to a given database, you must have the insert action on the admin database’s admin.system.users collection. The restore role provides this privilege.
To restore user-defined roles to a database, you must have the insert action on the admin database’s admin.system.roles collection. The restore role provides this privilege.
Basic mongorestore Operations¶
The mongorestore utility restores a binary backup created by mongodump. By default, mongorestore looks for a database backup in the dump/ directory.
The mongorestore utility restores data by connecting to a running mongod or mongos directly.
mongorestore can restore either an entire database backup or a subset of the backup.
To use mongorestore to connect to an active mongod or mongos, use a command with the following prototype form:
mongorestore --port <port number> <path to the backup>
Consider the following example:
mongorestore dump-2013-10-25/
Here, mongorestore imports the database backup in the dump-2013-10-25 directory to the mongod instance running on the localhost interface.
Restore Point in Time Oplog Backup¶
If you created your database dump using the --oplog option to ensure a point-in-time snapshot, call mongorestore with the --oplogReplay option, as in the following example:
mongorestore --oplogReplay
You may also consider using the mongorestore --objcheck option to check the integrity of objects while inserting them into the database, or you may consider the mongorestore --drop option to drop each collection from the database before restoring from backups.
Restore Backups to Non-Local mongod Instances¶
By default, mongorestore connects to a MongoDB instance running on the localhost interface (e.g. 127.0.0.1) and on the default port (27017). If you want to restore to a different host or port, use the --host and --port options.
Consider the following example:
mongorestore --host mongodb1.example.net --port 3017 --username user --password pass /opt/backup/mongodump-2013-10-24
As above, you may specify username and password connections if your mongod requires authentication.