Switch to MapR M5? :-) Just kidding. Simple way of solving this pre CDH4... NFS mount a directory from your SN and add it to your list of checkpoint directories. You may lose some data, but you should be able rebuild.
There is more to this, but its the basic idea on how to get a copy of your meta data. Sent from a remote device. Please excuse any typos... Mike Segel On Apr 18, 2012, at 11:48 PM, 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, > >
