@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    HardwareLayout that = (HardwareLayout) o;

    if (!clusterName.equals(that.clusterName)) {
      return false;
    }
    return datacenters.equals(that.datacenters);
  }
Finds Disk by hostname, port, and mount path.

@param hostname of datanode
@param port of datanode
@param mountPath of disk
@return Disk or null if not found.
ambry-clustermap/src/main/java/com/github/ambry/clustermap/HardwareLayout.java