replication member is using mongodump command to backup database collections one at time and then transport them to another site for DR. The mongodump process takes so long that it places the replication server hours behind in replication. Replication doesn't catch up before the next night's backup kicks off, which creates a slowdown during the backup until disk activity maxes out and backups and replication grind to a halt.

What can we do to improve dump performance?
What is our best option for performing backups in EC2?
Should we be setting up our drives differently?