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Hadoop >> mail # user >> formatting hdfs without user interaction


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Re: formatting hdfs without user interaction
On Fri, Sep 23, 2011 at 11:52 AM, <[EMAIL PROTECTED]> wrote:

> Hi Harsh,
>
> On 9/22/11 8:48 PM, "Harsh J" <[EMAIL PROTECTED]> wrote:
>
> >Ivan,
> >
> >Writing your own program was overkill.
> >
> >The 'yes' coreutil is pretty silly, but nifty at the same time. It
> >accepts an argument, which it would repeat infinitely.
> >
> >So:
> >
> >$ yes Y | hadoop namenode -format
> >
> >Would do it for you.
>
> Nice!  I read the man page for yes too quickly and did not see that
> option.  Thanks!
>
>
> >(Note that in the future release, saner answers will be acceptable,
> >i.e. y instead of strictly Y, etc.)
>
> Y/y/yes/YES would all seem like good things to accept :)
>
>
> >Also, two other things:
> >
> >- What do you mean by 'Yeah I have a secondary namenode as well so 2
> >directories.'? A secondary namenode uses different directories than
> >dfs.name.dir.
>
> Which parameter are you referring to? I am planning on using 2 directories
> in dfs.name.dir, one is local and the other is an NFS mount of a 2nd
> machine running the secondary namenode.
>
>
> >- The prompt only appears when it detects a 'reformat' being happening
> >- which is very dangerous to do non-interactively. If you do the
> >-format the first time, on clean dfs.name.dir setups, you will never
> >receive a prompt.
>
> Yeah I am creating some automation, so it needs to be able to wipe out an
> existing filesystem and start over......
>
>
> Cheers,
> Ivan
>
>
>
> >
>
>
You might want to try expect scripting. You open a stream to the process and
then can wait for prompts and print replies. expect also has this feature
autoexpect which is a shell that records the streams and turns your teminal
interaction into an expect script.