hadoop namenode多次格式化后，导致datanode启动不了

jps

hadoop namenode -format

 

dfs directory : /home/hadoop/dfs

• 　　--data
  • 　　--current/VERSION

  • #Wed Jul 30 20:41:03 CST 2014
    
    storageID=DS-ab96ad90-7352-4cd5-a0de-7308c8a358ff
    
    clusterID=CID-aa2d4761-974b-4451-8858-bbbcf82e1fd4
    
    cTime=0
    
    datanodeUuid=a3356a09-780c-43e8-a721-45aecf9bdb96
    
    storageType=DATA_NODE
    
    layoutVersion=-55

     

• 　　--name
  • 　　 --/current/VERSION

  • #Wed Jul 30 20:39:00 CST 2014
    
    namespaceID=895092439 clusterID=CID-aa2d4761-974b-4451-8858-bbbcf82e1fd4
    
    cTime=0
    
    storageType=NAME_NODE
    
    blockpoolID=BP-152997847-127.0.0.1-1406723940846
    
    layoutVersion=-56

     

• Block Pool
  
  
  
  A Block Pool is a set of blocks that belong to a single namespace.
  Datanodes store blocks for all the block pools in the cluster. 
  It is managed independently of other block pools. 
  This allows a namespace to generate Block IDs for new blocks without the need for coordination with the other namespaces. 
  The failure of a Namenode does not prevent the datanode from serving other Namenodes in the cluster.
  
  
  
  A Namespace and its block pool together are called Namespace Volume. 
  It is a self-contained unit of management. When a Namenode/namespace is deleted, 
  the corresponding block pool at the datanodes is deleted. Each namespace volume is upgraded as a unit, during cluster upgrade.
  
  
  
  ClusterID
  
  
  
  A new identifier ClusterID is added to identify all the nodes in the cluster. When a Namenode is formatted, 
  this identifier is provided or auto generated. This ID should be used for formatting the other Namenodes into the cluster.