Working with Multiple Groups
How do I Change Groups?
At MSI, we use unix groups to represent MSI “projects”. You might be in more than one MSI project, which means you have more than one unix group associated with your username. The below provides ways of switching which unix group/MSI project is currently active for your session.
You can see your current group by using the following command.
id -ng
You can change groups by using the following command, replacing groupname with the group you want to use.
newgrp <groupname>
The change will last for the duration of the login session only; to permanently change your primary group use the online change group tool.
To run a job on a different group, you may use the -A option in your Slurm script, replacing groupname with the group you want to use.
#!/bin/bash -l
#SBATCH -A <groupname>
If you have enabled trusted X11 forwarding by using the ssh -Y command, you must use the following commands to change groups. First, you must obtain the value of the DISPLAY variable in the original group.
echo $DISPLAY
Next, you must identify the corresponding xauth cookies by running the following command, replacing displaynumber with the number output from the previous step.
xauth list | grep \:<displaynumber>
Change to the new group with the newgrp command as explained above. Next, run the following commands, replacing displayvalue with the full value of the DISPLAY variable as output by the echo $DISPLAY command, and replacing xauthlistvalue with one of the lines from the xauth list command above.
export DISPLAY=<displayvalue>
xauth add <xauthlistvalue>
Note that you must run the xauth add command for each line output by the xauth list command. Another way to run a program under a different group is to use the sg command as shown below, replacing program with the program you’d like to run, and groupname with the name of the group under which you’d like to be running the program.
module load <program>
sg <groupname>
Additionally, if you would like to change groups within a Slurm script, you must include the last line in the header, replacing groupname with the name of the group under which you’d like to be running the script.
#!/bin/bash -l
#SBATCH -A groupname
Changing your Primary Group
If the majority of your work has transitioned to a new group, you may want to update your primary group to avoid the additional steps in order to work with that group. You can update your primary group here on myMSI by visiting the Change Group page.