private void deleteFromFs(final MasterProcedureEnv env, final TableDescriptor oldTableDescriptor,
    final TableDescriptor newTableDescriptor) throws IOException {
    final Set<byte[]> oldFamilies = oldTableDescriptor.getColumnFamilyNames();
    final Set<byte[]> newFamilies = newTableDescriptor.getColumnFamilyNames();
    for (byte[] familyName : oldFamilies) {
      if (!newFamilies.contains(familyName)) {
        MasterDDLOperationHelper.deleteColumnFamilyFromFileSystem(env, getTableName(),
          getRegionInfoList(env), familyName,
          oldTableDescriptor.getColumnFamily(familyName).isMobEnabled());
      }
    }
  }
Removes from hdfs the families that are not longer present in the new table descriptor.
@param env MasterProcedureEnv
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/ModifyTableProcedure.java