The this page explains how you can recover redundancy of ROMA.
Redundancy will down when some node was down.
Ex.) In case of ROMA have 3 nodes. host1_port1 host2_port1 host3_port1 And redundancy setting is 2.
When a node will down due to some troubles, redundancy of bucket will decrease.
Recovering the redundancy
Confirmation of redundancy
Confirm count of key which redundancy down by stat command from telnet.