No, I don't think it's a bug. Your datanodes' data partition/directory was probably used in other HDFS setup and thus had other namespaceID.
Or you could've used other partition/directory for your new HDFS setup by setting different values for "dfs.data.dir" on your datanode. But in this case, you can't access your old HDFS's data. On Thu, Jul 3, 2008 at 4:21 AM, Xuan Dzung Doan <[EMAIL PROTECTED]> wrote: > I was following the quickstart guide to run pseudo-distributed operations > with Hadoop 0.16.4. I got it to work successfully the first time. But I > failed to repeat the steps (I tried to re-do everything from re-formating > the HDFS). Then by looking at the log files of the daemons, I found out the > datanode failed to start because its namespaceID didn't match with the > namenode's. I after that found that the namespaceID is stored in the text > file VERSION under dfs/data/current and dfs/name/current for the datanode > and the namenode, respectively. The reformatting step does change > namespaceID of the namenode, but not for the datanode, and that's the cause > for the inconsistency. So after reformatting, if I manually update > namespaceID for the datanode, things will work totally fine again. > > I guess there are probably others who had this same experience. Is it a bug > in Hadoop 0.16.4? If so, has it been taken care of in later versions? > > Thanks, > David. > > > >
