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This shows you the differences between two versions of the page.

--- en:hpc [2022/07/04 09:48] – [Batch Processing of Tasks (SLURM)] grikiete
+++ en:hpc [2022/07/18 11:01] – [The Limits of Resources] grikiete
@@ Line 167: / Line 167: @@
 More about SLURM opportunities you can read [[https://slurm.schedmd.com/quickstart.html|Quick Start User Guide]].
+====== Interactive Tasks (SLURM) ======
+Interactive tasks can be done with the //srun// command:
+<code>
+$ srun --pty $SHELL
+</code>
+The above command will connect you to the compute node environment assigned to SLURM and allow you to directly run and debug programs on it.
+After the commands are done disconnect from the compute node with the command
+<code>
+$ exit
+</code>
+If you want to run graphical programs, you need to connect to **ssh -X** to **uosis.mif.vu.lt** and **hpc**:
+<code>
+$ ssh -X uosis.mif.vu.lt
+$ ssh -X hpc
+$ srun --pty $SHELL
+</code>
+In **power** cluster interactive tasks can be performed with
+<code>
+$ srun -p power --mpi=none --pty $SHELL
+</code>
+====== GPU Tasks (SLURM) ======
+To use GPU you need to specify additionally <code>--gres gpu:N</code> where N is desired GPU amount.
+With ''nvidia-smi'' in the task you can check the GPU amount that was dedicated.
+Example of an interactive task with 1 GPU:
+<code>
+$ srun -p gpu --gres gpu --pty $SHELL
+</code>
+====== Introduction to OpenMPI ======
+Ubuntu 18.04 LTS is the packet of **2.1.1** OpenMPI version.
+To use the newer version **4.0.1** you need to use
+<code>
+module load openmpi/4.0
+</code>
+before running MPI commands.
+===== MPI Compiling Programs =====
+An example of a simple MPI program is in the directory ''/scratch/lustre/test/openmpi''. **mpicc** (**mpiCC**, **mpif77**, **mpif90**, **mpifort**) is a framework for C (C++, F77, F90, Fortran) compilers that automatically adds the necessary **MPI** include and library files to the command line.
+<code>
+$ mpicc -o foo foo.c
+$ mpif77 -o foo foo.f
+$ mpif90 -o foo foo.f
+</code>
+===== Implementation of MPI Programmes =====
+MPI programs are started with **mpirun** or **mpiexec**. You can learn more about them with the **man mpirun** or **man mpiexec** command.
+A simple (SPMD) program can be started with the following mpirun command line.
+<code>
+$ mpirun foo
+</code>
+All allocated processors will be used according to the number ordered. If you want to use less, you can specify the -np quantity parameter in **mpirun**. It is not recommended to use less CPU than reserved for a longer time period, as unused CPUs remain free.
+**ATTENTION** It is strictly forbidden to use more CPU than you have reserved, as this may affect the performance of other tasks.
+Find more information on [[https://www.open-mpi.org|OpenMPI]].
+====== Task Efficiency ======
+  * Please use at least 50% of the ordered CPU quantity.
+  * Using more CPUs than ordered will not improve performance, as your task will only be able to use the CPUs ordered.
+  * If you use the ''--mem=X'' parameter, the task can reserve more **CPUs** in proportion to the amount of memory it wants. For example: if you order ''--mem=14000'' in the **main** queue, at least 2 CPUs will be reserved, unless other parameters specify more. If your task uses less than this, it will be an ineffective use of resources. In addition, it may run slower because it may use other memory than the executing CPU.
+====== The Limits of Resources ======
+If your tasks don't start because of **AssocGrpCPUMinutesLimit** or **AssocGrpGRESMinutes**,
+ you need to check if there are any unused CPU/GPU resources left from the monthly limit.
+**Pirmasis būdas peržiūrėti, kiek išnaudota resursų:**
+<code>
+sreport -T cpu,mem,gres/gpu cluster AccountUtilizationByUser Start=0101 End=0131 User=USERNAME
+</code>
+kur **USERNAME** - jūsų MIF naudotojo vardas, o **Start** ir **End** nurodo einamojo mėnesio pradžios ir pabaigos datas. Jas galima nurodyti ir kaip ''$(date +%m01)'' ir ''$(date +%m31)'', kas nurodo einamojo mėnesio pirmą ir paskutinę dienas.
+**DĖMESIO**: naudojimas pateikiamas minutėmis, pateiktą skaičių reikia dalinti iš 60, gausite išnaudotas valandas.
+**Antrasis būdas peržiūrėti, kiek išnaudota resursų:**
+<code>
+sshare -l -A USERNAME_mif -p -o GrpTRESRaw,GrpTRESMins,TRESRunMins
+</code>
+kur **USERNAME** - MIF naudotojo vardas. Arba parametre **-A** nurodyti tą paskyrą, kurios naudojimą reikia pažiūrėti. Duomenys yra pateikiami taip pat minutėmis:
+  * **GrpTRESRaw** - kiek išnaudota.
+  * **GrpTRESMins** - koks yra limitas.
+  * **TRESRunMins** - likę resursai dar vis vykdomų užduočių.
+====== Nuorodos ======
+  * [[waldur|HPC Waldur portalo aprašymas]]
+  * [[http://mif.vu.lt/itapc#paslaug%C5%B3-u%C5%BEsakymas|ITAPC paslaugų užsakymas]]
+  * [[https://slurm.schedmd.com/quickstart.html|Quick Start User Guide (SLURM)]]
+  * [[https://docs.qlustar.com/Qlustar/11.0/HPCstack/hpc-user-manual.html|HPC User Manual (Qlustar)]]
+  * [[http://www.mcs.anl.gov/research/projects/mpi/|MPI standartas]]
+  * pagalba@mif.vu.lt - problemų su **HPC** registracija