private IgniteHadoopFileSystem fileSystem() throws Exception {
  Configuration fsCfg=new Configuration();
  fsCfg.addResource(U.resolveIgniteUrl("modules/core/src/test/config/hadoop/core-site-loopback.xml"));
  fsCfg.setBoolean("fs.igfs.impl.disable.cache",true);
  if (logging)   fsCfg.setBoolean(String.format(PARAM_IGFS_LOG_ENABLED,"igfs:igfs-grid@"),logging);
  fsCfg.setStrings(String.format(PARAM_IGFS_LOG_DIR,"igfs:igfs-grid@"),U.getIgniteHome());
  return (IgniteHadoopFileSystem)FileSystem.get(new URI("igfs://igfs:igfs-grid@/"),fsCfg);
}

private IgniteHadoopFileSystem fileSystem ( ) throws Exception { Configuration fsCfg = new Configuration ( ) ; fsCfg . addResource ( U . resolveIgniteUrl ( "modules/core/src/test/config/hadoop/core-site-loopback.xml" ) ) ; fsCfg . setBoolean ( "fs.igfs.impl.disable.cache" , true ) ; if ( logging ) fsCfg . setBoolean ( String . format ( PARAM_IGFS_LOG_ENABLED , "igfs:igfs-grid@" ) , logging ) ; fsCfg . setStrings ( String . format ( PARAM_IGFS_LOG_DIR , "igfs:igfs-grid@" ) , U . getIgniteHome ( ) ) ; return ( IgniteHadoopFileSystem ) FileSystem . get ( new URI ( "igfs://igfs:igfs-grid@/" ) , fsCfg ) ; }
instantiate new file system .
