JLab Computer Center Linux Services: Supported Systems Types

Supported Linux System Types

What type of Linux systems does the Computer Center offer?

The Computer Center offers three types of Linux installations for you to choose from, all of which are built around the Red Hat Enterprise Linux (RHEL) product.

Level 1 Linux systems are entirely managed by the Computer Center, and are ideal for users who don't want to be bothered by common administrative hassles of fixing system problems, installing new software and keeping up with frequent security patches. These machines are managed directly by the Computer Center and offer the highest level of integration with the CUE machines like jlabl1, jlabs1 and the farm/ifarm machines.

Level 2 Linux machines, on the other hand, are designed for users who want or need to be root (superuser) on their own machines. The administrator of a Level 2 machine can choose their own root password, which means that they will be the primary administrator of the machine, with the freedom to reconfigure settings, add users, manage storage and install programs as they see fit. The Computer Center staff may assist them with specific tasks from time to time, but the responsibility for daily administration of the machine lies with the administrator, not the Computer Center. Level 2 machines will automatically be included in the patch management system maintained by the Computer Center, however, so at least Level 2 administrators will be relieved of this burden.

The third option, the Standalone configuration, is for experienced Linux administrators only. It provides the maximum amount of freedom by allowing the administrator not only to choose their own root password, but also to perform customized installations. Standalone administrators can choose a different list of installed software package, partition their hard drives differently, and generally have the highest level of control over their machines. On the downside, standalone machines are not well integrated into the CUE environment.

What are the differences between these systems?

	Pros	Cons
Level 1	+ Easy access to the same /home, /group, /site, /work, /scratch and /apps directories as jlabl1, jlabs1 and the farm/ifarm systems	- You will not be able to install your own software on the system, add users or manage other system settings without first contacting the Computer Center
	+ You share the same account across all CUE and scientific computing machines	- Won't work with your laptop
	+ Offload all the time-consuming system administration tasks to the Computer Center
	+ The computer is pre-configured for the best possible integration with the rest of the CUE and scientific computing machines
	+ Basic services like printing, DNS and NTP come pre-configured
	+ "Like having an ifarml1 on your desk"

Level 2	+ You will have the root password	- You will not have access to the /group directory, although specific group areas can be made available to you by request.
	+ You can install software, add users or manage other system settings without the assistance of the Computer Center	- Your /home directory will be local to the individual machine, and not shared with the rest of the CUE or scientific computing machines.
	+ Access to /site, /apps and /scratch directories.	- Won't work with your laptop
	+ The Computer Center handles security patches, saving you time
	+ Basic services like printing, DNS and NTP come pre-configured
	+ This configuration offers a good balance between local administrative privileges and integration with the rest of the CUE and scientific computing machines

Standalone	+ You will be the only administrator	- You will not have access to the /home, /group, /work or /scratch directories
	+ You can install software, add users or manage other system settings without the assistance of the Computer enter	- Your /home directory will be local to the individual machine, and not shared with the rest of the CUE or scientific computing machines.
	+ The Computer Center handles security patches, saving you time	- You will be required to manually configure certain systems settings to comply with JLab's published security and IT management policies, and ensure continuing compliance
	+ You will have access to the /scratch, /apps and /site directories	- You must configure basic services like printing, DNS and NTP yourself
	+ This option offers the maximum amount of flexibility to meet specialized computing needs	- This option offers very little integration with the rest of the CUE and scientific computing machines
	+ The best choice for laptops

Which type of system should I choose?

For most users, we recommend a Level 1 system. These systems are fully integrated into the CUE and scientific computing environment, so you can expect things to work on your desktop system the same way they will on the central machines. Your home directory is shared so all your files will be available to you in both places, and any code you write and test on your desktop will be compatible with the ifarml* machines and the batch farm. This is the best solution for most users, especially physicists and students who just want to concentrate on science.

If you are comfortable with Linux system administration and are willing to spend the extra time required to manage your own machine, the Level 2 system can be a viable choice. In return for the extra administration effort, you'll have the ability to manage the system in almost any way you choose. If your work requires you to install specialized software, interface with non-standard devices or if you just like bragging that you're root on your own box, a Level 2 system might be for you.

The Computer Center strongly recommends that you consider using either a Level 1 or a Level 2 system. Unless you're planning to install Linux on your laptop, most day-to-day computing requirements can be met by using one of these two configurations. In the event that neither of these work for you, you may attempt a standalone installation. Be aware, though, that the Computer Center is able to offer very little support for standalone machines, and that this option requires you to be an experienced Linux administrator. If you are considering choosing this option, please first contact the helpdesk at x7155 to discuss whether your requirements can be satisfied by a Level 1 or Level 2 system.

What if I have a Laptop?

Laptop users cannot use Level 1 or Level 2 Linux configurations. Laptops are mobile, and move from network to network while at the Lab, and are often taken offsite and used when not connected to the Lab's network. Level 1 and Level 2 systems require certain JLab network services to be available in order to run, and if they are used outside the JLab network, they will either not work at all, run slowly, or fail in other ways. If you need to use Linux on your laptop, you should be using a standalone configuration.

What if I have Windows installed already?

Installing Linux on your PC will erase Windows, along with all other files on the PC. Before installing Linux, be absolutely certain that you don't need Windows on that PC anymore. The Computer Center no longer allows dual-booting of Windows & Linux on the same computer.

Now that I know what I want, how do I get one installed?

Easy! See our Linux Installation Instructions page for more information on how to install RHEL on your computer.

This document is maintained by {helpdesk@jlab.org}