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

In order to provide a physical person with the possibility of running jobs on Mufasa, two operations are required:

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 uploading data and code in their /home directory.

The second operation is needed to enable 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, see Requesting user creation and/or registration.

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

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

where <username> and <research_group> are chosen as explained below (see Usernames and Group names).

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.

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 Mufasa, Linux groups are used to identify the research group that a specific user is part of.

In the command above, <research_group> must be one of the following:

• • cartcas for research group CartCasLab (prof. Cerveri);
  • biomech for research group Biomechanics Research Group (prof. Votta);
  • nearmrs for research group Medical Robotics Section of NearLab (prof. De Momi);
  • nearnes for research group 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.

Note that by using the command above, all users are also assigned group users, which is common to all Mufasa users corresponding to physical people.

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. This operation must necessarily be performed by Job Administrators.

See below for details.

Requesting user creation and/or registration

To request the creation of a Linux user and/or to ask for its registration in 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
• if such person is an M.Sc. student or a researcher (these include Ph.D. students)
• what research group the person belongs to, among those listed above
• (if already created) name of the Linux user corresponding to the person