Resources

High performance Computing (HPC)

IIT Delhi has a supercomputer called Padum. You can apply for a HPC account here. Recently, a new supercomputer called Pragya has been made available with the following features:

  • 50 Compute nodes, each with 8 x Nvidia A100 80 GB NVLink and 2 x 64 core AMD CPU with 1 TB RAM.
  • 2 additional nodes, each with 2 x Nvidia A100 80 GB PCI + 2 x 24 core AMD CPU+ 512 GB RAM.
  • 3 Login nodes, 2 x 24 core AMD CPU+ 512 GB RAM
  • Maximum 10 running and 10 queued jobs with a maximum wall time of 48 hours.
  • Request for access here

Login

Check HPC webpage on how to login and access the HPC. This is typically done using ssh, e.g.

ssh username@hpc.iitd.ac.in    # on padum
ssh username@pragya.iitd.ac.in # on pragya

Upon login, you will be assigned a login node. E.g. [username@loginXX] For first time users, initial setup is required.

Job submission

Please check HPC webpage for more details. You can use atoms.npn as the project_code

Interactive jobs

  • User Involvement: Active and real-time. The user inputs commands, and the system immediately processes and responds.
  • Connection Type: Requires an active terminal, web session, or display station connection. If the connection drops, the job often terminates.
  • Typical Use Cases: Installing software, running queries, text editors, Integrated Development Environments (IDEs), web browsing, and debugging code.
  • Advantage: Immediate results and flexibility for troubleshooting
  • You can login to compute nodes and run jobs interactively via these commands, e.g.
qsub -I -P project_code -lselect=1:ncpus=1:ngpus:1
  • You will be assigned a compute node. E.g. [username@amilan007]

Batch jobs

  • User Involvement: Zero to minimal. Instructions are compiled in a script or program ahead of time and queued.
  • Connection Type: Runs in the background. Users can disconnect or log out while the job processes; the system notifies the user upon completion.
  • Typical Use Cases: Most computational simulations, large-scale data analysis, etc.
  • Advantage: Maximizes CPU efficiency by running heavy processes without human delay.
  • You can find a sample ONETEP job submission script here

Internet access

The CSC machines and HPC are by default on intranet. To access external websites via internet, configure the proxy settings.

  • A sample bash script is supplied here.
  • Edit the proxy address. E.g. for Ph.D. students it is proxy61 while for M.Tech. use proxy62.
  • Run the script and enter your kerberos id and password.
$ bash proxy.sh
Enter IITD username: XXXXXXXXXXX
Enter IITD password: proxy login
  • Keep the session alive, and login to the HPC via another terminal. ssh to the same node as before where the interactive job and the internet is running. E.g. ssh amilan007. Set the environment variables by following commands:
export http_proxy=http://proxy[].iitd.ac.in:3128
export https_proxy=http://proxy[].iitd.ac.in:3128
  • Now, the internet should be active on your terminal. You can try commands like wget, etc. to download something from the web and check if the internet is working.

Software

Certain software is centrally installed on the HPC. For list of available softwares, please check available modules:

module avail

You can load the reqired software directly using

module load <package_name>

Installation

Softwares and versions not available on the HPC should be installed by the user in their accounts. Some points to keep in mind for installing new software:

  • Login to HPC.
  • Software should be installed and run on the compute node and not on the login node. To login to the compute node and install the software start an interactive job.
  • If the software is not already downloaded and needs to be downloaded from the internet using e.g. pip, wget, git, etc., please first enable the internet access and then download and install the software.
  • After installation and testing, exit the interactive job.

There are some software frequently used by the group, and instructions are available for them: