364. Setting up a new user on a ROCKS cluster

Because I keep forgetting about the rocks sync command...

From https://groups.google.com/forum/?fromgroups=#!topic/rocks-clusters/P6tvn_2Gk5Y

To add a new user to a ROCKS cluster and let them use Sun Grid Engine, do the following

sudo useradd -m verahill
sudo passwd verahill
su verahill
exit
sudo usermod -a -G compchem verahill
rocks sync users
qconf -auser verahill

      1 name verahill
      2 oticket 0
      3 fshare 0
      4 delete_time 0
      5 default_project NONE

where compchem is a usergroup I've set up to give everyone access to the executables they need.

The first login, using su above, creates the .ssh directory and rsa/dsa keys.

Finally, to force the user to change their password on first login, do

chage -d 0 verahill

363. Generating an image in PyMol

For some reason I needed to quickly generate a publication quality figure of a protein.

Deep View (SWiss PDB viewer) isn't available for linux anymore, and the old versions rely on 32 bit libs (which is increasingly a headache on debian). Rasmol is a classic, but I haven't used it properly since 1997 -- and all attempts at exporting png, jpg etc. failed on my debian wheezy box.

Jmol is awesome, and while I managed to make some pretty convincing figures I never quite got to where I wanted.

So I tried pymol

Pymol, like rasmol and jmol, has a visual interface which can be controlled via an integrated terminal. The learning curve is steep, but it's quick and easy to make figures once you've got the basics.

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Install pymol from the repos in debian:
sudo apt-get install pymol

(on Archlinux you can get it via AUR  -- you'll need to install python-pmw first)

Download 1SU4.pdb from here http://www.rcsb.org/pdb/explore.do?structureId=1su4

In the directory where your pdb file is, do

pymol 1SU4.pdb

select helices, chain A

Click on the A(ction) by (helices), select preset/publication.

 select calcium, (res 995-996)
 show spheres, calcium

 Note that 'helices' and 'calcium' are just handles or aliases that I made up.

 alter calcium, vdw=5
 show spheres, calcium

 color purple calcium
 bg_color white

 set antialias=1
 set sphere_mode=5

where sphere_mode 5 means shading.

 ray 1000,1000

 save 1SU4.png

And here's the final figure:

362. Sun Grid Engine: Limit number of running jobs for a user

I don't like copying a post verbatim, but I also want to make sure that I keep track of what I do on my shared cluster, and that I don't forget how to set user based job limits.

Andi Broka made an excellent post at https://lists.sdsc.edu/pipermail/npaci-rocks-discussion/2010-November/049905.html in which two methods were shown (see below).

Resource quota management in general is covered here these days: http://docs.oracle.com/cd/E19957-01/820-0698/gehwk/index.html

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1. Number of running jobs: limit for ALL users
Modify the scheduler configuration:

qconf -msconf

2 schedule_interval                 0:0:15
3 maxujobs                          0
4 queue_sort_method                 load

Change maxujobs from 0 (unlimited) to a suitable value.

The m in -msconf stands for modify, conf stands for configuration, and the s stands for scheduler.

2. Number of running jobs: limit for a particular user
Modify the resource quota set(s):

qconf -mrqs

1 {
2    name         verahill
3    description  "specific limitations for user verahill"
4    enabled      TRUE
5    limit        users verahill to slots=40
6 }

Again, the -m is for modify, and rqs is for resource quota set(s).

Note that slots are the number of processes and not nodes -- 40 slots allows me to use five 8-core nodes.