public DiskHealthStatus getDiskHealthStatus() {
    return diskHealthStatus;
  }
A callback to invoke when a blob store encountered several io error and shut down itself. In this case,
we should test all blob stores on this disk. If it's indeed a disk error, all blob stores would be forced
to shut down themselves and enter ERROR state. Later disk failure handler would pick it up and move all
the replica out to a different place in FULL AUTO.
ambry-store/src/main/java/com/github/ambry/store/DiskManager.java