我在hadoop群集中的一个或两个节点中发现了此错误，其中其他节点运行正常：

ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException:  

***********Upgrade is not supported from this older version of storage to 

the current version. Please upgrade to Hadoop-0.14 or a later version and 
then upgrade to current version. Old layout version is 'too old' and latest 
layout version this software version can upgrade from is -7.

你知道如何在不丢失数据的情况下解决这个问题吗？