Users

Only Mufasa users (i.e., people with a user account on Mufasa) can access the machine and interact with it.

This page explains how to create new users and what is user policy on Mufasa.

Creating new Mufasa users

In order to provide a physical person with the possibility of running jobs on Mufasa, two operations must be executed:

1. the person must be assigned a new Linux user on Mufasa
2. the new Linux user must be registered in SLURM's accounting system

The first operation only enables the person to interact with Mufasa via SSH and to execute basic activities, such as loading data and code in their /home directory.

The second operation is allows the person to fully exploit Mufasa's computational resources, which requires using The SLURM job scheduling system.

Creating a new Linux user

Creation of new Linux users is done either by Job Administrators or by specially designated users within each research group. If you are not one of these, write to Giulio Fontana.

Mufasa users who have the power to create new users do so with command

sudo  /opt/share/sbin/add_user.sh -u <user> -g users,<group>

where <user> is the username of the new user and <group> is one among the groups described in Users and groups, i.e. cartcas, biomech, nearmrs, nearnes, bio.

For instance, in order to create a user on Mufasa for a person named Mario Rossi belonging to CartCasLab, the following command will be used:

sudo /opt/share/sbin/add_user.sh -u mrossi -g users,cartcas

At first login, new users will be asked to change the password initially assigned to them. For security reason, it is important that such first login occurs as soon as possible after user creation.

Providing new users with access to SLURM

New users are not able to Execute jobs via SLURM until they are properly registered in SLURM's accounting system.

In order to register with SLURM a new Linux user (and possibly also require the creation of such user) a person belonging to the academic staff in charge of Mufasa should write to Giulio Fontana.

The request will need to contain the following information:

• name and surname of the person who needs to use SLURM
• if the person is a M.Sc. student or a researcher (these include Ph.D. students
• what research group the person belongs to
• name of the Linux user (if already created)

Users and groups

Mufasa usernames have the form xyyy (all lowercase), where x is the first letter of the first name of the person, and yyy is their complete surname. For instance, a person called Mario Rossi will be assigned username mrossi. If multiple users with the same surname and first letter of the first name exist, those created after the very first one are given usernames including a two-digit counter: mrossi, mrossi01, mrossi02 and so on.

On Linux machines such as Mufasa, users belong to groups. On Mufasa, groups are used to identify the research group that a specific user is part of. Assigment of Mufasa's users to groups follow these rules:

• All users corresponding to people belong to group users
• Additionally, each user must belong to one and only one of the following groups (within brackets is the name of the faculty who is in charge of Mufasa for each group):
  • cartcas, i.e. CartCasLab (prof. Cerveri);
  • biomech, i.e. Biomechanics Research Group (prof. Votta);
  • nearmrs, i.e. Medical Robotics Section of NearLab (prof. De Momi);
  • nearnes, i.e. NeuroEngineering Section of NearLab (prof. Ferrante);
  • bio, for BioEngineering users not belonging to any of the research groups listed above.