public static boolean exists(Configuration conf, FileSystem fs, RegionInfo info)
    throws IOException {
    Path rootDir = CommonFSUtils.getRootDir(conf);
    Path regionDir = FSUtils.getRegionDirFromRootDir(rootDir, info);
    return fs.exists(regionDir);
  }
Returns True if the Region exits in the filesystem.
hbase-server/src/main/java/org/apache/hadoop/hbase/backup/HFileArchiver.java