By just changing the configs will not effect your data. You need to restart your DNs to connect to new NN.
For the second question: It will again depends on your usage. If your files will more in DFS then NN will consume more memory as it needs to store all the metadata info of the files in NameSpace. If your files are more and more then it is recommended that dont put the NN and JT in same machine. Coming to DN case: Configured space will used for storing the block files.Once it is filled the space then NN will not select this DN for further writes. So, if one DN has less space should fine than less space for NN in big clusters. Configuring good configuration DN which has very good amount of space. And NN has less space to store your files metadata info then its of no use to have more space in DNs right :-) Regards, Uma ----- Original Message ----- From: praveenesh kumar <praveen...@gmail.com> Date: Thursday, September 22, 2011 10:42 am Subject: Re: Can we replace namenode machine with some other machine ? To: common-user@hadoop.apache.org > If I just change configuration settings in slave machines, Will it > effectany of the data that is currently residing in the cluster ?? > > And my second question was... > Do we need the master node (NN/JT hosting machine) to have good > configuration than our slave machines(DN/TT hosting machines). > > Actually my master node is a weaker machine than my slave > machines,because I > am assuming that master machines does not do much additional work, > and its > okay to have a weak machine as master. > Now I have a new big server machine just being added to my > cluster. So I am > thinking shall I make this new machine as my new master(NN/JT) or > just add > this machine as slave ? > > Thanks, > Praveenesh > > > On Thu, Sep 22, 2011 at 10:20 AM, Uma Maheswara Rao G 72686 < > mahesw...@huawei.com> wrote: > > > You copy the same installations to new machine and change ip > address.> After that configure the new NN addresses to your > clients and DNs. > > > > >Also Does Namenode/JobTracker machine's configuration needs to > be better > > >than datanodes/tasktracker's ?? > > I did not get this question. > > > > Regards, > > Uma > > > > ----- Original Message ----- > > From: praveenesh kumar <praveen...@gmail.com> > > Date: Thursday, September 22, 2011 10:13 am > > Subject: Can we replace namenode machine with some other machine ? > > To: common-user@hadoop.apache.org > > > > > Hi all, > > > > > > Can we replace our namenode machine later with some other > machine. ? > > > Actually I got a new server machine in my cluster and now I want > > > to make > > > this machine as my new namenode and jobtracker node ? > > > Also Does Namenode/JobTracker machine's configuration needs to be > > > betterthan datanodes/tasktracker's ?? > > > > > > How can I achieve this target with least overhead ? > > > > > > Thanks, > > > Praveenesh > > > > > >
