CentOS Linux at CSE
CentOS is a community-supported open source project, which produces a free derivative of the RedHat Enterprise Linux (RHEL) distribution. CentOS mainly varies from RHEL in logos and branding. The CS Lab installs CentOS on most of the lab-managed Linux machines, both research and instructional.
CentOS releases are derived from the sources of RedHat Enterprise Linux. New CentOS releases generally lag new RHEL releases by a few weeks. Like RHEL, CentOS releases have a multi-year life cycle, with periodic 'point releases', which may introduce new features and provide package version updates for some key software components.
We adopt a new major release of CentOS some time after its release, once we have tested it and integrated it into our distribution environment. The rollout to our various systems can afford to be somehat leisurely, as the previous CentOS version is still being maintained, typically for several more years.
What we install
The software packages are chosen when the Linux distribution is prepared. We typically install most packages that CentOS considers 'standard' and 'mandatory' for basic usage, along with additional packages that provide a rich development environment for writing, documenting, and running code. The package set varies from release to release, as RHEL (and hence CentOS) adds and removes packages, and as our departmental needs and focus change over time.Some of the key components of our Linux systems include:
- Kerberos for password authentication
- NFS for home and project directories (made available via an automounter)
- SAMBA for file service and xfreerdp for desktop access to departmental Windows machines
- Secure logins via ssh or kerberos
- OpenJDK for our java offering
- LibreOffice for our office productivity offering
- Various revision control packages (git, rcs, cvs, subversion, mercurial)
- GNOME and XFCE desktop environments
For the latest list of installed software on any given system, run the command rpm -qa.
The software set for a particular Linux release is mostly the same across the various research machines, although there can be some differences. Instructional systems have additional 'couseware' installed. Courseware software is a set of additional packages, requested by instructors prior to the start of each quarter. As such, the courseware packages vary from quarter to quarter and year to year. Most of the courseware comes from standard CentOS packages, although some are obtained from other sources and generally require special packaging and integration.
Additional software (non Courseware)
If you want a software package that isn't available, you can request it. We will always evaluate your request. If CentOS supplies the package and the software doesn't conflict with what is currently installed, we can generally accommodate your request. However, we do not promise to do so and if we decline the request we will give you a reason why. Software not provided by CentOS has less chance of being installed (unless it is requested as courseware). Such software involves additional man power for packaging and maintaining, and it sometimes does not nicely coexist with other packages on the installed system. Requests for newer versions of software also tend to be problematical, as the CentOS versions are often requirements for other installed packages and cannot be overwritten or superseded without causing an adverse ripple effect.
We openly discourage binary only non-open source software, as it often involves potentially complicated licensing. and may adversely inhibit our ability to perform upgrades in a timely fashion.
Users may install their own versions of any appropriately licensed software in non-system areas, such as home directories, project directories, machine specific scratch directories.
Software maintenance is on-going. CentOS provides package updates which we apply in a timely fashion. These updates generally include bug fixes and security fixes, along with incremental upgrades for some of the package set. CentOS point releases introduce more significant changes. We also apply these point releases in a timely fashion, once they have received proper scrutiny.
Root Privileges and NFS mounts
Only CS Lab staff have root privileges on Lab managed Linux systems.
NFS mounts from Lab managed Linux file servers are only available to other lab managed Unix machines. User managed machines can gain access to file server data via Samba or sshFS.