Frequently Asked Questions


Q. What is the procedure to get an access to the supercomputing facility at IUAC?

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Q. What are KALKI and K2?

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Q. How do I connect to KALKI and K2?


Q. What is the hardware and OS configuration of the supercomputing facility at IUAC?

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Q. How do I submit jobs on KALKI or K2?

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    For submitting jobs on KALKI/K2, use only the qsub command. Your job will be submitted through the Sun Grid Engine resource manager. The sample qsub script for KALKI should work on K2 as well for most applications.
    For example, if your script name is "sample_script.txt" you should give the following command to submit it:

           $ qsub sample_script.txt

    For a sample qsub script, look here.

Q. How do I change the queue and parallel environment in the KALKI qsub script?

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    To decide which queue you should use, check out the queue management policy here. Then edit/insert into the qsub script something like these lines:

    #$ -q all.q

    #$ -cwd

    #$ -pe mpich 16

    The first line specifies the use of the "all.q" queue for calculations.

    The second line tells to work in the Current Working Directory (cwd) and the third line tells to use MPICH parallel environment with 16 cores.

    On Kalki, the other parallel environment available is the OpenMPI ORTE (-pe orte 8). Since the KALKI compute nodes have 8 cores each, this also means use one whole machine or node to do the calculations. On K2, please use multiples of 16 as the core count.
Q. How do I find out how many cores are free on KALKI and K2?

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    The following command tell you how many cores are available on various queues:

    qstat -g c
Q. What are the limits on number of cores and time for various queues?
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             For K2, please see this page.