Basics

Before diving into the different functionalities of GRAVITON and the usage of the job scheduler (SLURM), it is important to understand some basic aspects of the system that all users should be familiar with.

Directories

Each user has a unique, personal, and non-transferable home directory located at:

[username@grui01 ~]$  /lhome/ific/u/username

Here, username corresponds to your actual user ID. These personal directories are organized in subfolders based on the first letter of the username. For example, a user with the name username, which starts with a u, will have a home directory under /lhome/ific/u/.

In addition to personal directories, GLUON project directories are also available and synchronized on GRAVITON. If you are also a GLUON user, you will have write access to the corresponding group directories.

These shared directories can be found at:

[username@grui01 ~]$  /lustre/ific.uv.es/prj/gl

Within this path, each research group has its own subdirectory. Most GRAVITON users belong to one or both of the SOM subgroups within GLUON: mosayco and somlat.

To check your group memberships, you can use the id command:

[username@grui01 ~]$  id

Useful Commands

This section describes some useful commands available for interacting with GRAVITON.

Graviton Quota

grquota is a script to retrieve user quota information in the GRAVITON system.

Usage:

[username@glui01 ~]$ grquota

Description:

  • Retrieves the quota for the user in /lhome/ific/.

  • Lists the GLUON groups the user belongs to and checks if they have a Lustre project directory.

  • If the group has a Lustre directory, it displays its quota.

Example Output:

--------------------------------------------------------
Disk quotas for user username (uid 12345):
      Filesystem  space   quota   limit   grace   files   quota   limit   grace
/lhome/ific/u     10G     50G     60G     -       1000    5000    6000    -
--------------------------------------------------------
Disk quotas for project 6010:
      Filesystem  space   quota   limit   grace   files   quota   limit   grace
/lustre/ific.uv.es/prj/gl     500G    1T      1.2T    -       50000   100000  120000  -
--------------------------------------------------------

Graviton Status

grstatus is a monitoring script used to check the current status of the GRAVITON nodes.

Usage:

[username@grui01 ~]$ grstatus

Description:

  • Displays the number of allocated and total CPUs per node.

  • Shows the allocated and total memory for each node in the GRAVITON infrastructure.

  • The information is retrieved directly from SLURM metrics using scontrol, ensuring accurate and up-to-date status reporting.

This tool is particularly useful for users and administrators to quickly assess the system load and available resources across the cluster.

Example Output:

NODE         ALLOC_CPU  TOTAL_CPU  ALLOC_MEM  REAL_MEM
grwn01       0          56         0          245000
grwn02       0          56         0          245000
grwn03       0          56         0          245000
grwn04       0          56         0          245000
grwn05       0          56         0          245000