@Override
  public int hashCode() {
    int result = dataNode.hashCode();
    result = 31 * result + mountPath.hashCode();
    return result;
  }
An implementation of {@link DiskId} to be used within the {@link StaticClusterManager}.

A Disk stores {@link Replica}s. Each Disk is hosted on one specific {@link DataNode}. Each Disk is uniquely
identified by its DataNode and mount path (the path to this Disk's device on its DataNode).
ambry-clustermap/src/main/java/com/github/ambry/clustermap/Disk.java