Restore a Replica Set from MongoDB Backups¶
This procedure outlines the process for taking MongoDB data and restoring that data into a new replica set. Use this approach for seeding test deployments from production backups or as part of disaster recovery.
You cannot restore a single data set to three new mongod instances and then create a replica set. If you copy the data set to each mongod instance and then create the replica set, MongoDB will force the secondaries to perform an initial sync. The procedures in this document describe the correct and efficient ways to deploy a restored replica set.
Restore Database into a Single Node Replica Set¶
Obtain backup MongoDB Database files.¶
The backup files may come from a file system snapshot. The MongoDB Cloud Manager produces MongoDB database files for stored snapshots and point in time snapshots. For Ops Manager, an on-premise solution available in MongoDB Enterprise Advanced, see also the Ops Manager Backup overview.
Start a mongod instance for a new single-node replica set. Specify the path to the backup data files with --dbpath option and the replica set name with the --replSet option. For config server replica set (CSRS), include the --configsvr option.
mongod --dbpath /data/db --replSet <replName>
Add Members to the Replica Set¶
MongoDB provides two options for restoring secondary members of a replica set:
- Manually copy the database files to each data directory.
- Allow initial sync to distribute data automatically.
If your database is large, initial sync can take a long time to complete. For large databases, it might be preferable to copy the database files onto each host.
Use the following sequence of operations to “seed” additional members of the replica set with the restored data by copying MongoDB data files directly.
Update Secondaries using Initial Sync¶
Use the following sequence of operations to “seed” additional members of the replica set with the restored data using the default initial sync operation.