From ALICE Documentation
An important point about the diagram above is that ALICE clusters are a collection of shared, finite resources. When you connect to the login nodes, you are sharing their resources (CPU cycles, memory, disk space, network bandwidth, etc.) with a few dozen other researchers. The same is true of the file servers when you access your home or project directories, and can even be true of the compute nodes.
For most day-to-day activities you should not have to worry about this, and we take precautions to limit the impact that others might have on your experience. That said, there are a few use cases that are worth watching out for:
- The login nodes should only be used for light computation; any CPU- or memory-intensive operations should be done using the batch system. A good rule of thumb is that if you wouldn't want to run a task on your desktop because it would slow down other applications, you shouldn't run it on the login nodes. (See also: Interactive Jobs.)
- I/O-intensive jobs should copy their files to fast, temporary storage, such as the local storage allocated to jobs or the Scratch parallel file system.
In general, we just encourage our users to remember that what you do may affect other researchers on the system. If you think something you want to do or try might interfere with the work of others, we highly recommend that you contact us at email@example.com (mail request).