Can I set more than one dfs.name.dir?

[[EMAIL PROTECTED]]

Hi all:
        I found that I can set more than one dfs.name.dir in hadoop-site.xml
like below:
<property>
  <name>dfs.name.dir</name>
  <value>/opt/hadoop/dfs/name1</value>
  <value>/opt/..../name2</value>
  <description>Determines where on the local filesystem the NDFS name
node
     should store the name table.</description>
</property>

Does this mean I have a backup of my namenode info? Or this is for some
other special reasons?

Best Regards,

Jianglei
2006-11-24