LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices

Reply
 
Search this Thread
Old 07-03-2008, 01:38 PM   #1
m2azer
Member
 
Registered: Sep 2004
Location: USA
Distribution: red hat, fedora & centos
Posts: 202

Rep: Reputation: 30
Cluster - Hpc


Hello all,

I am setting up a cluster, 1 head node and 8 child nodes, in brief I am using ssh keys, MPICH and mounting the master /home on all child nodes.

I have to create each user account on all master and child nodes. Is there a way to only create users "accounts" on the "Master" and all the other child nodes would be aware of the new user.

I had a crazy idea about mounting the "Master" /etc folder on all child nodes then on each child node I would create a "ln -s" link for each of "passwd", "group" and "shadow" to /etc folder.

Thanks
 
Old 07-03-2008, 07:50 PM   #2
PatrickNew
Senior Member
 
Registered: Jan 2006
Location: Charleston, SC, USA
Distribution: Debian, Gentoo, Ubuntu, RHEL
Posts: 1,148
Blog Entries: 1

Rep: Reputation: 48
I see no particular reason why that shouldn't work. You'll probably have to hack up some sort of script to handle booting - in case you run into chicken and egg problems about being unable to mount without logging in and being unable to log in without mounting. Maybe you can just mount in an init script to avoid that though.
 
Old 07-03-2008, 08:30 PM   #3
sundialsvcs
Guru
 
Registered: Feb 2004
Location: SE Tennessee, USA
Distribution: Gentoo, LFS
Posts: 5,377

Rep: Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108Reputation: 1108
Usually, clusters and such grow too large to easily support authentication and authorization systems like this. It's simply too hard to manage, because you can't manage it centrally.

For this reason, authentication and authorization are often handled using systems like LDAP, which Microsoft refers to as "Active Directory." There are also more-aggressive systems like Kerberos.

The concept is that you have "directory servers," either masters or slaves, that are scattered around your network. Computers are set up to ask them for answers to questions like these:
Quote:
"May a user who has presented the username 'x' with the password 'y' gain access to me? And if so, exactly what may he do?"
These systems provide a well-thought-out mechanism by which a computer can securely solicit such a question, and get a trustworthy answer, even when operating on a network that is deemed to be insecure and therefore untrustworthy. Quite an amazing trick.

Your goal, however, is simply to arrange for your computer to take advantage of those "alternate" authentication and authorization mechanisms ... without imposing headaches either upon yourself or upon your applications. Fortunately, Linux provides an elegant solution to that (separate) problem.

Linux systems have a built-in mechanism called PAM ("P"luggable "A"uthentication "M"odules) which is specifically designed to provide the flexibility that's needed here.
  1. Applications, like login, "ask PAM" for an answer.
  2. PAM is actually a set of rules-files, residing on the local computer, which your computer now applies.
  3. In "standard Linux," these rules would cause the computer to consult (say...) the "shadow password-file" to get the answer.
  4. On your computers, however, you've installed a different set of PAM-rules... rules that cause your computer to instead consult LDAP, or Kerberos or whatever, to get the answer to the question.
  5. The bottom-line is, "login gets his answer," thumbs-up or thumbs-down, just like every single PAM-aware application in your computer is able to do and in exactly the same way. But you, the systems administrator, have complete flexibility to specify, behind the scenes, exactly how that "answer" will be determined. Your actions will apply uniformly to every PAM-aware program, and "they don't have to know and they don't have to care."

Last edited by sundialsvcs; 07-03-2008 at 08:33 PM.
 
  


Reply

Tags
clustering, computing, high, hpc, nfs, performance, useradd


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
petaFLOPS HPC Linux Clustering jorro_bg LinuxQuestions.org Member Intro 1 10-20-2007 10:38 AM
LXer: Penguin Computing's Scyld ClusterWare(TM) HPC Offers Enhanced High Availability and Most Advanced Linux Cluster Virtualization, Enabling Broader Cluster Use LXer Syndicated Linux News 0 04-06-2006 06:03 PM
LXer: Army makes major Linux HPC cluster move LXer Syndicated Linux News 0 02-13-2006 05:46 PM
LXer: Where is the Cluster? Microsoft HPC at SC05 LXer Syndicated Linux News 0 02-06-2006 12:02 PM
RedHat HPC aburosea Linux - Enterprise 8 06-01-2005 12:17 PM


All times are GMT -5. The time now is 07:11 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration