Address of the bookmark: http://huanglab.phys.hust.edu.cn/hnadock/

The following table shows SLURM commands on the SOE cluster.

For more information, run man on the commands above. See some examples below.

1. Info about the partitions and nodes
List all the partitions available to you and the nodes therein:

sinfo

Nodes in state idle can accept new jobs.

Show a partition configuratuin, for example, SOE_main

scontrol show partition=SOE_main

Show current info about a specific node:

scontrol show node=<nodename>

You can also specify a group of nodes in the command above. For example, if your MPI job is running across soenode05,06,35,36, you can execute the command below to get the info on the nodes you are interested in:

scontrol show node=soenode[05-06,35-36]

An informative parameter in the output to look at would be CPULoad. It allows you to see how your application utilizes the CPUs on the running nodes.

2. Submit scripts
The header in a submit script specifies job name, partition (queue), time limit, memory allocation, number of nodes, number of cores, and files to collect standard output and error at run time, for example

#!/bin/bash

#SBATCH --job-name=OMP_run     # job name, "OMP_run"
#SBATCH --partition=SOE_main   # partition (queue)
#SBATCH -t 0-2:00              # time limit: (D-HH:MM) 
#SBATCH --mem=32000            # memory per node in MB 
#SBATCH --nodes=1              # number of nodes
#SBATCH --ntasks-per-node=16   # number of cores
#SBATCH --output=slurm.out     # file to collect standard output
#SBATCH --error=slurm.err      # file to collect standard errors

If the time limit is not specified in the submit script, SLURM will assign the default run time, 3 days. This means the job will be terminated by SLURM in 72 hrs. The maximum allowed run time is two weeks, 14-0:00.
If the memory limit is not requested, SLURM will assign the default 16 GB. The maximum allowed memory per node is 128 GB. To see how much RAM per node your job is using, you can run commands sacct or sstat to query MaxRSS for the job on the node - see examples below.
Depending on a type of application you need to run, the submit script may contain commands to create a temporary space on a computational node - see the discussion about using the file systems on the cluster.
Then it sets the environment specific to the application and starts the application on one or multiple nodes - see sbatch sample scripts in directory /usr/local/Samples on soemaster1.hpc.rutgers.edu.
You can submit your job to the cluster with sbatch command:

sbatch myscript.sh

3. Query job information
List all currently submitted jobs in running and pending states for a user:

squeue -u <username>

Command squeue can be run with format options to expose specific information, for example, when pending job #706 is scheduled to start running:

squeue -j 706 --format="%S"

START_TIME
2015-04-30T09:54:32

More info can be shown by placing additional format options, for example:

squeue -j 706 --format="%i %P %j %u %T %l %C %S"

JOBID PARTITION   NAME    USER STATE   TIMELIMIT  CPUS START_TIME
706   SOE_main  Par_job_3 mike PENDING 3-00:00:00 64   2015-04-30T09:54:32

To see when all the jobs, pending in the queue, are scheduled to start:

squeue --start 

List all running and completed jobs for a user

sqlog -u <username>

or

sqlog -j <JobID>

The following appreviations are used for the job states:

       CA   CANCELLED      Job was cancelled.

       CD   COMPLETED      Job completed normally.

       CG   COMPLETING     Job is in the process of completing.

       F    FAILED         Job termined abnormally.

       NF   NODE_FAIL      Job terminated due to node failure.

       PD   PENDING        Job is pending allocation.

       R    RUNNING        Job currently has an allocation.

       S    SUSPENDED      Job is suspended.

       TO   TIMEOUT        Job terminated upon reaching its time limit.

You can specify the fields you would like to see in the output of sqlog:

sqlog --format=list

The command below, for example, provides Job ID, user name, exit state, start date-time, and end date-time for job #2831:

sqlog -j 2831 --format=jid,user,state,start,end

List status info for a currently running job:

sstat -j <jobid>

A formatted output can be used to gain only a specific info, for example, the maximum resident RAM usage on a node:

sstat --format="JobID,MaxRSS" -j <jobid>

To get statistics on completed jobs by jobID:

sacct --format="JobID,JobName,MaxRSS,Elapsed" -j <jobid>

To view the same information for all jobs of a user:

sacct --format="JobID,JobName,MaxRSS,Elapsed" -u <username>

To print a list of fields that can be specified with the --format option:

sacct --helpformat

For example, to get Job ID, Job name, Exit state, start date-time, and end date-time for job #2831:

sacct -j 2831 --format="JobID,JobName,State,Start,End"

Another useful command to gain information about a running job is scontrol:

scontrol show job=<jobid>

4. Cancel a job
To cancel one job:

scancel <jobid>

To cancel one job and delete the TMP directory created by the submit script on a node:

sdel <jobid>

To cancel all the jobs for a user:

scancel -u <username>

To cancel one or more jobs by name:

scancel --name <myJobName>

Then I thaught it migh be a problem of graphical display and I opened the terminal out of curiosity, and I found out that there is no ~/Desktop folder at all. What happened? What do I need to do?

Then I google the problem and found this is a very common problem after updates. To fix this problem, follow these steps:

You need to edit the ~/.config/user-dirs.dirs file, and make sure the contents of the file are like the following:

XDG_DESKTOP_DIR="$HOME/Desktop"
XDG_DOWNLOAD_DIR="$HOME/Downloads"
XDG_TEMPLATES_DIR="$HOME/"
XDG_PUBLICSHARE_DIR="$HOME/Share"
XDG_DOCUMENTS_DIR="$HOME/Documents"
XDG_MUSIC_DIR="$HOME/Music"
XDG_PICTURES_DIR="$HOME/Pictures"
XDG_VIDEOS_DIR="$HOME/Videos"

Then restart nautilus:

killall nautilus

or

nautilus -q

Then, open nautilus via Unity menu (press the Super key) or using the run command (Alt+F2)

In this tutorial, we will show you how to install and configure Elgg social networking platform on Ubuntu 20.04.

Prerequisites

• A fresh Ubuntu 20.04 VPS on the Atlantic.net Cloud Platform
• A valid domain name pointed to your server IP
• A root password configured on your server

Step 1 – Create Atlantic.Net Cloud Server

First, log in to your Atlantic.Net Cloud Server. Create a new server, choosing Ubuntu 20.04 as the operating system with at least 2GB RAM. Connect to your Cloud Server via SSH and log in using the credentials highlighted at the top of the page.

Once you are logged in to your Ubuntu 20.04 server, run the following command to update your base system with the latest available packages.

apt-get update -y

Step 2 – Install Apache, MariaDB and PHP

Elgg runs on Apache web server, is written in PHP, and uses MySQL/MariaDB as a database backend, so you will need to install the Apache, MariaDB, PHP and other required PHP extensions to your server. You can install all of them with the following command:

apt-get install apache2 mariadb-server php libapache2-mod-php php-common php-sqlite3 php-curl 
php-intl php-mbstring php-xmlrpc php-mysql php-gd php-xml php-cli php-zip unzip wget -y

After installing all the packages, edit the php.ini file and change some recommended settings.

nano /etc/php/7.4/apache2/php.ini

Change the following values:

max_execution_time = 300
memory_limit = 512M
upload_max_filesize = 100M
date.timezone = Asia/Kolkata

Save and close the file, then restart the Apache service to apply the configuration changes.

systemctl restart apache2

Step 3 – Create a Database for Elgg

Next, you will need to create a database and user for Elgg. First, log in to MySQL shell with the following command:

mysql

Once logged in, create a database and user with the following command:

CREATE DATABASE elgg;
CREATE USER 'elgg'@'localhost' IDENTIFIED BY 'secure-password';

Next, grant all the privileges to the elgg database with the following command:

GRANT ALL ON elgg.* TO 'elgg'@'localhost' IDENTIFIED BY 'secure-password' WITH GRANT 
OPTION;

Next, flush the privileges and exit from the MariaDB shell with the following command:

FLUSH PRIVILEGES;
EXIT;

At this point, the MariaDB database is created for Elgg.

Step 4 – Install Elgg

First, download the latest version of Elgg from its official website using the following command:

wget https://elgg.org/download/elgg-3.3.13.zip

Once the download is completed, unzip the downloaded file with the following command:

unzip elgg-3.3.13.zip

Next, move the extracted directory to the Apache root directory:

mv elgg-3.3.13 /var/www/html/elgg

Next, create a data directory and set proper ownership and permissions to the Elgg directory:

mkdir /var/www/html/data
chown -R www-data:www-data /var/www/html/elgg
chown -R www-data:www-data /var/www/html/data
chmod -R 755 /var/www/html/elgg

Once you are finished, you can proceed to the next step.

Step 5 – Configure Apache for Elgg

Next, you will need to configure Apache to serve Elgg. You can configure it by creating a new Apache virtual host configuration file:

nano /etc/apache2/sites-available/elgg.conf

Add the following lines:

<VirtualHost *:80>
ServerAdmin admin@example.com
DocumentRoot /var/www/html/elgg/
ServerName elgg.example.com
Options FollowSymLinks
AllowOverride All
ErrorLog /var/log/apache2/elgg-error_log
CustomLog /var/log/apache2/elgg-access_log common
</VirtualHost>

Save and close the file, then enable the virtual host and Apache rewrite module with the following command:

a2ensite elgg.conf
a2enmod rewrite

Finally, restart the Apache service to apply the changes:

systemctl restart apache2

Step 6 – Access Elgg Web Interface

Now, open your web browser and access the Elgg web interface using the URL http://elgg.example.com. You should see the Elgg welcome screen: