Red Hat Enterprise Linux 6

Red Hat Enterprise 6 is the latest release of the Red Hat Enterprise Linux (RHEL) operating system supported by the Computer Systems Lab for the Computer Sciences department.

There is a documentation page for RHEL 6, which contains more information about the new OS. Please visit the CSL web site (http://www.cs.wisc.edu/csl/) and click the "Red Hat Enterprise 6 Information" link.

If you're not sure what version of linux your computer is currently running, you can verify this by looking at the contents of the file '/etc/redhat-release'.

As always, please contact the lab (email lab@cs.wisc.edu) if you have any questions.

What Features Are Available?

Gnome 2.28 is the default desktop environment for RHEL 6.

RHEL 6 uses a 2.6.32-series kernel.

Other new software includes Google Chrome and Mozilla Firefox 10ESR internet web browsers.

How Much Disk Space Will I Have?

The default Red Hat Enterprise 6 install requires approximately 70 GBytes of disk space. The balance is left in /scratch for local storage.

What Are The Differences In Available Software?

Wherever possible, all programs that were available on previous linux distributions will also be available for RHEL 6. There are some situations where support has been dropped for a program either by Red Hat or by upstream maintainers. The CSL will deal with these on a case-by-case basis.

In the past, many programs that were available in /s/std/bin were also available in /usr/bin. Because of the increase in the volume of software installed, the nature of security vulnerabilities, and in an effort by the CSL to make the best possible use of resources, it has become impractical to maintain this duplication. Most software that is available in /usr/bin will not be available /s/std/bin. The CSL will continue to provided needed up-to-date software in /s (e.g. gcc, perl, python, and others) for those that need these updates.

Only 64-bit OS installs are supported. 32-bit compatability RPMs are available on an as-needed basis.

Release Notes

• vendor release notes: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.2_Release_Notes/index.html

The following caveats exist with RHEL 6. Workarounds are listed if known.

emacs does not start

In your favorite editor, open up ~/.Xresources. Remove any lines that contain emacs.Font. Save and run xrdb load ~/.Xresources or log out and back in. Emacs should now work.

Requesting an OS upgrade/change

To request an OS upgrade for your workstation or servers, please use the Request an OS Upgrade/Change web form

Remote Access

Remote access is available to supported RHEL6 workstations via the following methods:

SSH

Users are able to use an SSH client to connect securely to RHEL6 workstations. Due to issues with Kerberos and AFS authentication, using ssh with shared keys is not supported.

VNC

There are several methods by which users can get access to a remote desktop via VNC.

For non-instructional workstations, users can configure the Gnome remote desktop service to access their desktop remotely. When logged in, use the utility at System->Preferences->Remote Desktop for further configuration.

Users can also start the vncserver binary manually and connect to the session that is created. Please note that when you log out, that session may lose AFS authentication and you will need to 'kalog ' to re-gain authentication.

Instructional workstations (mumble-1.cs.wisc.edu through mumble-40.cs.wisc.edu) also have an additional service where VNC connections made to the following hosts are load-balanced.

mumble-vnc-small.cs.wisc.edu
mumble-vnc-medium.cs.wisc.edu
mumble-vnc-wide.cs.wisc.edu

Please note that all VNC connections must either be through an SSH tunnel or via the Computer Sciences VPN.

Remote Desktop

It is also possible to connect to the instructional linux workstations (mumble-1.cs.wisc.edu through mumble-40.cs.wisc.edu) using windows remote desktop services. The connections are persistent based upon screen resolution and must use the Computer Sciences VPN for connection.

Remote X application display

X applications can also be displayed remotely when X11 is tunneled via SSH. This is often a checkbox option in Windows SSH clients, or easily enable using the "-X" option in the command line ssh client. (e.g. ssh -X hostname.cs.wisc.edu ) Windows users will additionall need to install X server software, such as Xming to display remote X applications on their local display.