This isn't possible to do. DN holds no metadata about what file the block belongs to.
Redundant copies (2-3, at least one off-machine) of dfs.name.dir, aside from has not proven bad in recovery situations in my experience yet. You should be just fine with adequate redundancy and suitably periodic checkpoints. On Thu, Apr 19, 2012 at 10:18 AM, Saburo Fujioka <fuji...@do-it.co.jp> wrote: > Hello, > > I do a tentative plan of operative trouble countermeasures > of a system currently now. > > If when NameNode has been lost, but are investigating the > means to rebuild the remaining NameNode from DataNode, > I don't know at the moment. > > Were consistent with those of the DataNode is the namespaceID > of "dfs/name/current/ VERSION" as confirmation, > "fsimage" are not rebuilt, the list did not display anything > in the "hadoop dfs-ls". > > The risk of loss for NameNode because that is protected by > "Corosync + Pacemaker + DRBD" is low. > Because of the rare case, it is necessary to clarify the means > to reconfigure the NameNode from DataNode. > > Do you know how to? > > > I am using hadoop 1.0.1. > > Thank you very much, > -- Harsh J
