Users

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

Creating new Mufasa users

For a person to become a Mufasa user, two steps are required:

Step 1 - a new Linux user must be created for the person on Mufasa

This enables the person to access Mufasa and to execute basic activities, such as uploading data or code to their /home directory.

Step 2 - the new Linux user must be registered to SLURM's accounting system

This enables the person to fully exploit Mufasa's computational resources, which requires using SLURM.

For this, a request must be made as explained below.

Requesting user creation and/or registration

To request the creation of a new Linux user and/or its registration to SLURM's accounting system, a person belonging to the academic staff in charge of Mufasa should write to Giulio Fontana.

The request needs to specify what follows:

• name and surname of the person that the Linux user is associated to
• email of the person
• user category, which can be either student (for M.Sc. students) or a researcher (for everyone else, including Ph.D. students)
• what research group the person belongs to, among those listed in Group names
• (if a Linux user has already been created for the person) username

User and groups on Mufasa

This section explains user and group policy on Mufasa, and the procedure to create new users and associate them to groups.

Usernames

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.

Group names

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 physical people belong to group users
• Additionally, each user must belong to one and only one of the following groups:
  • 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.

The person cited within brackets is the faculty who is in charge of Mufasa for each group.

In the command for user creation described below, <research_group> must be one among cartcas, biomech, nearmrs, nearnes, bio.

Creating a new Linux user

Creation of new users on Mufasa can be done by Job Administrators or by specially designated users within each research group.

User creation is done with command

sudo  /opt/share/sbin/add_user.sh -u <username> -g users,<research_group>

where <username> and <research_group> are chosen as explained in Usernames and Group names respectively.

For instance, in order to create a user on Mufasa for a person named Mario Rossi belonging to research group 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 a user with access to SLURM

New users are not able to execute jobs via SLURM until they are properly registered to SLURM's accounting system. This operation must necessarily be performed by Job Administrators.

See Requesting user creation and/or registration for details.