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Please remember that different projects are usually active on different hosts. With the "saldo -b" command you can list all the account_no associated to your username. On systems like MARCONI, where different partitions are available on the same environment, you need to specify the host name in the "saldo" command:

> saldo -b (reports projects defined on Marconi-SKL - default)

> saldo -b --knl (reports projects defined on Marconi-KNL)

> saldo -b --skl (reports projects defined on Marconi-SKL)

Budget Linearization policy

On MARCONI a linearization policy for the usage of project budgets has been defined and implemented. For each account, a monthly quota is defined as:

monthTotal = (total_budget / total_no_of_months)

Starting from the first day of each month, the collaborators of any account are allowed to use the quota at full priority. As long as the budget is consumed, the jobs submitted from the account will gradually lose priority, until the monthly budget (monthTotal) is fully consumed. At that moment, their jobs will still be considered for execution, but with a lower priority than the jobs from accounts that still have some monthly quota left.

This policy is similar to those already applied by other important HPC centers in Europe and worldwide. The goal is to improve the response time, giving users the opportunity of using the cpu hours assigned to their project in relation of their actual size (total amount of core-hours).

Accounting

For accounting information please consult our dedicated section.

The account_no (or project) is important for batch executions. You need to indicate an account_no to be accounted for in the scheduler, using the flag "-A"

#SBATCH -A <account_no>

Please remember that different projects are usually active on different hosts. With the "saldo -b" command you can list all the account_no associated to your username. 

> saldo -b (reports projects defined on M100 )

Budget Linearization policy

On M100 a linearization policy for the usage of project budgets has been defined and implemented. For each account, a monthly quota is defined as:

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A $WORK area is defined for each active project on the system, reserved for all the collaborators of the project. This is a safe storage area to keep run time data for the whole life of the project.

$DRES environment variable points to the shared repository where Data RESources are maintained. This is a data archive area available only on-request, shared with all CINECA HPC systems and among different projects. $DRES is not mounted on the compute nodes. This means that you cannot access it within a batch job: all data needed during the batch execution has to be moved to $WORK or $CINECA_SCRATCH before the run starts.

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In order to detect all profiles, categories and modules available on M100 the command “modmap” is available:

>modmap

Spack

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Production environment

Since M100 is a general purpose system and it is used by several users at the same time, long production jobs must be submitted using a queuing system. This guarantees that the access to the resources is as fair as possible.
Roughly speaking, there are two different modes to use an HPC system: Interactive and Batch. For a general discussion see the section Production Environment and Tools.

Interactive

A serial program can be executed in the standard UNIX way:

> ./program

This is allowed only for very short runs, since the interactive environment has a 10 minutes time limit: for longer runs please use the "batch" mode.

A parallel program can be executed interactively only within an "Interactive" SLURM batch job, using the "srun" command: the job is queued and scheduled as any other job, but when executed, the standard input, output, and error streams are connected to the terminal session from which srun was launched.

For example, to start an interactive session with the MPI program myprogram, using one node, two processors, launch the command:

> srun -N1 -n2 --ntasks-per-node=2 -A <account_name> --pty /bin/bash

add gpu version?

SLURM will then schedule your job to start, and your shell will be unresponsive until free resources are allocated for you.

When the shell come back with the prompt, you can execute your program by typing:

> srun ./myprogram

or

> mpirun ./myprogram

The srun command will take by default PMI2 as MPI type.

Please note that

1) The recommended way to launch parallel tasks in slurm jobs is with srun. By using srun vs mpirun you will get full support for process tracking, accounting, task affinity, suspend/resume and other features.

2) Controlling the processes and threads affinity is crucial to ensure the optimal performances on M100. Do not rely on slurm autoaffinity and use the proper SLURM --cpu-bind option 

SLURM automatically exports the environment variables you defined in the source shell, so that if you need to run your program "myprogram" in a controlled environment (i.e. specific library paths or options), you can prepare the environment in the origin shell being sure to find it in the interactive shell.

Batch

The info reported here refer to the general M100 partition. The production environment of MARCONI_Fusion is discussed in a separate document.

As usual on systems using SLURM, you can submit a script script.x using the command:

> sbatch script.x

You can get a list of defined partitions with the command:

> sinfo

You can simplify the output reported by the sinfo command specifying the output format via the "-o" option. A minimal output is reported, for instance, with:

> sinfo -o "%10D %20F %P"

which shows, for each partition, the total number of nodes and the number of nodes by state in the format "Allocated/Idle/Other/Total".

IMPORTANT:

1. Please note that the recommended way to launch parallel tasks in slurm jobs is with srun. By using srun vs mpirun you will get full support for process tracking, accounting, task affinity, suspend/resume and other features.
2. Controlling the processes and threads affinity is crucial to ensure the optimal performances on Marconi-A2 and Marconi-A3. Do not rely on slurm autoaffinity and use the proper SLURM --cpu-bind option. 

For more information and examples of job scripts, see section Batch Scheduler SLURM.

Submitting Batch jobs