我试过hadoop-1.0.3和1.0.4。都在伪集群模式下。
我的理解是previous.checkpoint目录应该在“fs.checkpoint.dir”指定的辅助名称节点下创建？在任何情况下，我都会在“dfs.name.dir”指定的namenode目录下找到它。这跟伪模式有关还是我的理解有误？有人能帮忙吗！
下面是我的hdfs-site.xml文件。

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<!-- Put site-specific property overrides in this file. -->

<configuration>
    <property>
        <name>dfs.replication</name>
        <value>1</value>
    </property>
    <property>
        <name>dfs.name.dir</name>
        <value>/home/hadoop/lab/hdfs/namenode</value>
    </property>
    <property>
        <name>dfs.data.dir</name>
        <value>/home/hadoop/lab/hdfs/datanode</value>
    </property>
    <property>
        <name>fs.checkpoint.dir</name>
        <value>/home/hadoop/lab/hdfs/secnamenode</value>
    </property>
</configuration>

下面是守护程序的高级目录结构

hadoop@ubuntu:~/lab/hdfs$ ls -l
total 12
drwxr-xr-x 6 hadoop hadoop 4096 Mar 14 03:41 datanode
drwxrwxr-x 5 hadoop hadoop 4096 Mar 14 03:41 namenode
drwxrwxr-x 4 hadoop hadoop 4096 Mar 14 04:46 secnamenode

下面是namenode目录的详细信息

hadoop@ubuntu:~/lab/hdfs$ ls -l namenode
total 12
drwxrwxr-x 2 hadoop hadoop 4096 Mar 14 04:46 current
drwxrwxr-x 2 hadoop hadoop 4096 Mar 14 03:13 image
-rw-rw-r-- 1 hadoop hadoop    0 Mar 14 03:41 in_use.lock
drwxrwxr-x 2 hadoop hadoop 4096 Mar 14 03:34 previous.checkpoint

下面是snn目录的详细信息

hadoop@ubuntu:~/lab/hdfs$ ls -l secnamenode
total 8
drwxrwxr-x 2 hadoop hadoop 4096 Mar 14 04:46 current
drwxrwxr-x 2 hadoop hadoop 4096 Mar 14 03:46 image
-rw-rw-r-- 1 hadoop hadoop    0 Mar 14 03:41 in_use.lock

如果你需要更多的细节，请告诉我。
谢谢，破布