Thanks for the update, I understand now that I'll be installing a "secondary
name node" which performs checkpoints on the primary name node and keeps a
working backup copy of the fsimage file.

The primary name node should write its fsimage file to at least 2 different
physical mediums for improved safety as well (example: locally and an nfs

One point of query: were the primary name node to be lost, we would be best
off re-building it and copying the fsimage files into place, either from the
nfs share, or from the secondary name node, as the situation dictates.
There's no mechanism to "fail over" to the "secondary name node" per-se.

Am I on track here?

-----Original Message-----
From: Konstantin Shvachko [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, March 27, 2013 5:07 AM
Subject: Re: For a new installation: use the BackupNode or the

There is no BackupNode in Hadoop 1.
That was a bug in documentation.

Here is the updated link:


On Sat, Mar 23, 2013 at 12:04 AM, varun kumar <[EMAIL PROTECTED]> wrote:
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