<description>The number of seconds between two periodic checkpoints. </description>
</property>
<property>
<name>fs.checkpoint.size</name>
<value>67108864</value>
<description>The size of the current edit log (in bytes) that triggers a periodic checkpoint even if the fs.checkpoint.period hasn't expired. </description>
</property>
<property>
<name>fs.checkpoint.dir</name>
<value>/data/work/hdfs/namesecondary</value>
<description>Determines where on the local filesystem the DFS secondary name node should store the temporary images to merge. If this is a comma-delimited list of directories then the image is replicated in all of the directories for redundancy. </description>
<description> The address and the base port where the dfs namenode web ui will listen on. If the port is 0 then the server will start on a free port. </description>
在使用start-balancer.sh时,
默认使用1M/S(1048576)的速度移动数据(so slowly...)
修改hdfs-site.xml配置,这里我们使用的是20m/S
<property>
<name>dfs.balance.bandwidthPerSec</name>
<value>20971520</value>
<description> Specifies the maximum bandwidth that each datanode can utilize for the balancing purpose in term of the number of bytes per second. </description>
</property>
我问一下,我将namenode进程kill掉之后,通过hadoop namenode –importCheckpoint 启动namenode时报:ERROR namenode.FSNamesystem: FSNamesystem initialization failed.
java.io.IOException: Cannot import image from a checkpoint. NameNode already contains an image in /opt/hadoop/name
at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:320)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.loadFSImage(FSDirectory.java:104)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initialize(FSNamesystem.java:427)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:395)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:299)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:569)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1479)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1488)
14/03/10 16:55:00 ERROR namenode.NameNode: java.io.IOException: Cannot import image from a checkpoint. NameNode already contains an image in /opt/hadoop/name
at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:320)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.loadFSImage(FSDirectory.java:104)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initialize(FSNamesystem.java:427)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:395)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:299)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:569) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1479)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1488)
你遇到过这种情况吗?