public static HRegion createHRegion(Configuration conf, RegionInfo regionInfo, FileSystem fs,
    Path tableDir, TableDescriptor tableDesc) throws IOException {
    LOG.info("Creating {}, tableDescriptor={}, under table dir {}", regionInfo, tableDesc,
      tableDir);
    HRegionFileSystem.createRegionOnFileSystem(conf, fs, tableDir, regionInfo);
    HRegion region = HRegion.newHRegion(tableDir, null, fs, conf, regionInfo, tableDesc, null);
    return region;
  }
Create a region under the given table directory.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java