You can perform an IntelliSnap full backup operation of MongoDB databases in both replica set and sharded cluster MongoDB deployments. During the IntelliSnap backup, we quiesce the databases and take snapshots of the database mount paths.
Backup Node Selection
To perform backups, nodes from the secondary nodes list are selected based on their priority. The node with the lowest priority is selected for backup by default. You can add additional settings so that either the node with the least lag or with the least priority is selected for backups, see Selecting Nodes for MongoDB Backups.
For more information on how to set priority of nodes in a replica set or a sharded cluster, go to the MongoDB documentation website.
Backup of Incremental Changes
The MongoDB operation logs are periodically dumped to local staging locations on secondary nodes. Based on threshold criteria such as the disk use percentage and the number of operation log dumps generated, the backup jobs are triggered on the staging locations to capture incremental changes. The default local staging location for operation logs is software_installation_path/iDataAgent/jobResults/subclient_id directory.
If you want to disable operation log dump backups, you must add an additional setting. For more information, see Disabling Operation Log Dump Backups.
What Is Backed Up
All the data that is present in the dbpath of the server is backed up from the secondary nodes. To back up incremental changes, you must configure operation log backups, For more information, see Configuring a MongoDB Subclient to Back Up Operation Log Dumps.