Insufficient Oplog Size Error

When using the Cloud Manager interface to back up a MongoDB cluster, Cloud Manager checks to see if the cluster’s oplogs are, based on their recent usage, large enough to hold a minimum of 3 hours worth of data based on the last 24 hours of usage patterns. If the oplogs are not large enough, it may be possible that the oplogs may have turned over multiple times, creating a gap between where a backup ends and an oplog starts.

If the oplog size check fails, the user cannot enable backups and is shown the warning:


Insufficient oplog size: The oplog window must be at least 3 hours over the last 24 hours for all members of replica set <name>. Please increase the oplog.

If possible, wait to start a backup until the oplog has had sufficient time to meet the size requirement.