[Beowulf] Resources for starting a Beowulf Cluster (NFS Setup?)

[Robert G. Brown]

On Wed, 20 Jun 2007, A Lenzo wrote:

> Hello all,
>
> I am new to Linux and need help with the setup of my Beowulf Cluster.  Can
> anyone suggest a few good resources?
>
> Here is a description of my current hurdle: I have 1 master node and 2 slave
> nodes.  For starters, I would like to be able to create a user account on
> the master node and have it appear on the slave nodes.  I've figured out
> that the first step is to copy over several files as follows:
>
> /etc/group
> /etc/passwd
> /etc/shadow
>
> And this lets me now log into any node with a given password, but the home
> directory of that given user does not carry over.

I'd suggest getting a good book on Unix/Linux systems administration at
your local friendly bookstore.  Most of this is standard stuff for
managing any LAN, and the one by Nemeth, Snyder and Hein (Linux
Administration Handbook) is likely as good as any.

You want to:

   a) NFS export your home directory from the master.  Basically this
involves making an entry in /etc/exports (with PRECISELY the right
format, sorry, RTMP) and doing chkconfig nfs on, /etc/init.d/nfs start.
God willing and the crick don't rise, and after you turn off selinux
completely and drive a stake through its heart and use
system-config-security to enable at least NFS in addition to ssh, then
with luck you'll be able to go to a node/client and do:

   mount -t nfs master:/home /home

(and add a suitable line to /etc/fstab to make this automagical on boot)
and have it "just work".

   b) There are two ways to handle the user account, password,
/etc/hosts, and other system db synchronization.  For a tiny cluster
with one or two users they are pretty much break even.  One is to do
what you've done -- create e.g. /etc/[passwd,group,shadow,hosts] on the
master and then rsync them to the nodes as root, taking care not to
break them or you'll be booting them single user to clean them up or
reinstalling them altogether!  When a new account is added, rerun the
rsyncs.  You can even write a tiny script that will rsync exactly what
is needed.  Or, you can learn to use NIS, which scales to a much larger
(department/organization sized) enterprise and cluster with dozens or
hundreds of user accounts.

For that you'll NEED the systems administration book or one like it --
NIS is not for the faint of heart.  I've done NIS management before, and
know how to use it, but elect to go the other way for my home
LAN/cluster because even 8-10 systems and 4-5 users are about break even
compared to a judicious and infrequent set of rsyncs, and a cluster is
even simpler in this regard.  FWIW, local (non-NIS) dbs are somewhat
faster for certain classes of parallel operation although this is not
generally a major issue for most code.

Hope this helps,

    rgb

>
> All comments welcome!
>
> Thanks!
> A Lenzo
>
> PS - I am using Fedora Core 6.
>
> _______________________________________________
> Beowulf mailing list, Beowulf at beowulf.org
> To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
>

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu