1. NameNode can be directly formatted, but the data in this NameNode will all no (available for cluster blank exercise, other times not recommended)
2. Shut down the cluster sbin / stop-all.sh, where the machine will secondaryNameNode the fsimage and edits files are copied to namenode where fsimage and edits to the following folder because of my secondaryNameNode and namenode installed on the same machine, in node01 above, execute the following command to copy node01
cp -r / Export / Servers / hadoop- cdh5.14.0-2.6.0 / hadoopDatas / DFS / SNN / name / * /export/servers/hadoop-2.6.0-cdh5.14.0/hadoopDatas/namenodeDatas/
CP -R & lt /export/servers/hadoop-2.6.0- cdh5.14.0 / hadoopDatas / the DFS / nn / SNN / edits / * /export/servers/hadoop-2.6.0-cdh5.14.0/hadoopDatas/dfs/nn/edits
3. open cluster sbin / start-all.sh
