That is an excellent question. It is trivial to back up a live SQL Server instance because it supports shadow-volume snapshots. The same isn't true for MongoDB.
Instead, we had to resort to running our MongoDB database on a 3-node cluster and this is our main strategy for resiliency. Additionally, one of the nodes is set to do a daily full-database dump, which is pretty much guaranteed to be in an inconsistent state but still provides us an extra degree of peace of mind.
Instead, we had to resort to running our MongoDB database on a 3-node cluster and this is our main strategy for resiliency. Additionally, one of the nodes is set to do a daily full-database dump, which is pretty much guaranteed to be in an inconsistent state but still provides us an extra degree of peace of mind.