MogileFS::ReplicationPolicy::Union -- satisfy 2 or more replication policies

Use this replication policy to satisfy multiple replication policies. For instance:

    Union(MultipleHosts(3), OnDevice(7))

Would make sure a class' files replicate on 3 unique hosts, and are also on device 7 (which is perhaps your backup device).

MogileFS::Worker::Replicate

MogileFS::ReplicationPolicy

MogileFS::ReplicationPolicy::MultipleHosts

MogileFS::Class