UWMLSC > Beowulf Systems > Medusa

Adding a user to the Medusa cluster

The green text in the following instructions should be replaced by the appropriate values. These instructions are not intended to replace man pages. They extend that information to a protocol to be followed on Medusa.
  1. Assemble the username, uid, gid, certificate info, contact info (email and phone), data group requirements, for the new user. These values must be chosen according to the rules laid out in the user/group table. This table is automatically generated; when you add a user to the requisite system files, they will appear in this table.

  2. Log into medusa.phys.uwm.edu as your superuser account (skflasch, shammerd, sparmor, etc). This account should have root privileges.

  3. Add the user with the addnisuser script. You can find this script in the tools CVS repository, accessible at the console or on our public CVS page. If for some reason you have problems accessing this, you can download it here, but be warned this may not be as up to date as the version in CVS. Usage of the script is simple:

         ./addnisuser uid gid username machine

    gid: 500-UWMLSC 502-external

    where machine is the value uwmlsc (likely if the user is internal) or storage1 (likely if the user is external).

  4. Manually add human readable name to /var/yp/ypfiles/passwd file.

  5. Add the user to the appropriate data groups in /var/yp/ypfiles/group. Then

        cd /var/yp/ ; make

  6. Put the new versions of auto.home and the nis passwd file (both updated in the last step) in the CVS repository. To do this, copy /var/yp/ypfiles/auto.home, /var/yp/ypfiles/group and /var/yp/ypfiles/passwd into the masterconfig/master001/configfiles/var/yp/ypfiles directory in the 7.3install CVS repository and commit it.

  7. Backup the updated user account files:


  8. Add the following line to the /etc/aliases file:

         username: username@some.address.edu

    Then run the command


  9. Put the new version of /etc/aliases in the CVS repository. To do this, copy /etc/aliases into the masterconfig/master001/configfiles/etc directory in the 7.3install CVS repository and commit it.

  10. Log out of medusa.phys.uwm.edu

  11. If the user being added is an external user, log into storage1.phys.uwm.edu as root and do the following:

         mkdir /export1/homes/username
         cp /etc/skel/.* /export1/homes/username
         cd /export1/homes
         chown --recursive uid.gid username

    [note: skip this step if the user is internal - a different procedure is assumed]

  12. Log out of storage1.phys.uwm.edu

  13. Add the user to the appropriate grid-mapfile. Ask Paul (or Scott) where these are stored.

  14. Add the user to the userpriorites script on condor. Set the priority to the appropriate value, and check the file into cvs.

  15. Add the users contact info (phone, email) to the appropriate files on uwmlsc (/var/yp/ypfiles/voice /var/yp/ypfiles/email. These files then need to be checked into CVS. See "Updating uwmlsc NIS domain" docs on the computing page. Then do a cd /var/yp/ ; make.

  16. ssh root@dataserver

  17. su - datarobot ignore the error: bash: /etc/globus-user-env.sh: No such file or directory

  18. Add cert into to /opt/LDR/ldr/etc/grid-mapfile.LDRdataFindServer

  19. logout of dataserver

  20. Using a web browser, go to the medusa-users administrative page. Log in and add the new user to the e-mail list. This is an important step, since announcements about maintanence schedules and other important information for users goes to this list. If you do not know the password, email Patrick.

  21. Test the new account to make sure it works.

  22. Send the following text to the user (please edit appropriately and provide necessary details):
    You have been granted an account on our Beowulf system here at UWM.
    Here is the information:
    username:  joeuser
    machine:   hydra.phys.uwm.edu
    We are encouraging users to connect to the Medusa cluster using Grid
    tools and have made available a number of RPMs that you can easily
    install. The RPMs include Grid-enabled versions of SSH and FTP. Please
    for links to the RPMs along with full instructions on how to install
    and use the Grid tools.
    Currently the Medusa cluster has 296 slave nodes and a number of
    master nodes, but you MUST log into hydra and not one of the other
    masters.   We have a web page with documentation regarding accessing the 
    cluster.  Documentation for users is minimal, but under development, so 
    suggestions are welcome:
    Your home directory is visible from all machines,  so you should be
    able to pick up auxilliary files from there as you need to.   If you
    have problems with the system,  please submit a problem report by
    going to our web page and following the link at the top of the
    navigation bar; use guest/guest as the user/passwd and change the
    database toggle switch to medusa.   We will deal with the issue as
    time permits.  Please attempt to understand the classifications of
    bugs and use the appropriate urgency identification.
    If you have requested it, we will also given you an ldas user/passwd
    here at UWM sometime in the next day or two.
    To get started using a shared object, you should build LAL and
    LALWrapper on our system in your home directory according to the most
    recent howto document.  Once you have completed the build,   you can
    access your dso by
    -dynlib /home/joeuser/lib/lalwrapper/libldasXXX.so
    where XXX is replaced by the appropriate name.
    Also,  a couple of rules about our system:
    1.  Please do not write output to your home directory, this may cause 
    noticable performance issues.  See #2.
    2.  Please do not keep large amounts of data in your home directory.
    We back up the home directories once a week and do not have the
    resources to deal with problems at this time.   If you want to store
    data temporarily use the space in /scratch which is accessible from
    all nodes.
    3.  Please be aware that the computer you log into is used by several
    people.  Please don't run major code on it.  Use it for compiling and
    minimal testing.
    4.  If you have a very urgent problem,  please e-mail 
    medusa-admin@gravity.phys.uwm.edu about it.
    Welcome to the UWM Medusa cluster!
    The UWM-LSC Group
  23. After the user has downloaded the Grid tools RPMs and has obtained a X.509 certificate he/she is instructed to send medusa-admin the Distinguished Name from his/her certificate. Edit the grid-mapfile /etc/grid-security/grid-mapfile on hydra and add the Distinguished Name along with the mapping to the local username. Follow the syntax of the names already in the file. Each line should be of the form

         "/O=Grid/O=Globus/OU=UWM/CN=Scott Koranda" skoranda

$Id: adding_a_user.html,v 1.46 2005/05/25 21:50:05 elemenoh Exp $

Check this page for dead links, sloppy HTML, or a bad style sheet; or strip it for printing.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.