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MapReduce >> mail # user >> Re: Recovering the namenode from failure


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Re: Recovering the namenode from failure
Hi David,

You shouldn't need to do anything to get your DNs to report in -- as best
they can tell, it's the same NN. Do you see any error messages in the DN
logs?

-Todd

On Tue, May 21, 2013 at 12:30 AM, David Parks <[EMAIL PROTECTED]>wrote:

> I’m on CDH4, and trying to recover both the namenode and cloudera manager
> VMs from HDFS after losing the namenode.****
>
> ** **
>
> All of our backup VMs are on HDFS, so for the moment I just want to hack
> something together, copy the backup VMs off HDFS and get on with properly
> reconfiguring via CDH Manger.****
>
> ** **
>
> So I’ve installed a plain ‘ol namenode on one of my cluster nodes and
> started it with –importCheckpoint (with the data from the secondary NN),
> this seems to have worked, I have a namenode web UI up which expects to
> find 32178 blocks.****
>
> ** **
>
> But my plain namenode (on the same hostname and IP as the old namenode)
> says that there are no datanodes in the cluster.****
>
> ** **
>
> What do I need in order to configure the datanodes to report their blocks
> into this new namenode (same IP & hostname)?****
>
> ** **
>
> Thanks,****
>
> David****
>
> ** **
>

--
Todd Lipcon
Software Engineer, Cloudera