Linux at SLAC

	Linux at SLAC	SLAC Computing UNIX at SLAC LINUX-L Archives
	Updated: 26 Feb 2008

SLAC's recommended Linux for all machines is Red Hat Enterprise Linux (RHEL). Currently, most SLAC Linux systems are running version 3 of RHEL (RHEL 3) but version 4 (RHEL 4) is also supported. Only the 32-bit version of RHEL 3 is supported at SLAC; both 32-bit and 64-bit versions of RHEL4 are supported. Note that software built under RHEL4 will not run on a RHEL3 system; likewise, software built on a RHEL4/64-bit system won't run on a RHEL4/32-bit machine.

Version 5 (RHEL 5) has recently been released by Red Hat, but it is not yet supported at SLAC. (Note that an earlier version, RHEL 2.1, has never been supported at SLAC.)

SLAC has negotiated a site subscription to RHEL and has also purchased a support contract from Red Hat, which has proven quite valuable. In addition to helping us resolve a number of problems it has also given us early access to new releases and a voice in Red Hat's future directions.

Scientific Linux

Scientific Linux (SL) is a free Linux distribution provided by FNAL and other labs and universities. It should be 100% compatible with Red Hat Enterprise Linux. The versions available at SLAC are SL 3 and SL 4.

BaBar has adopted Scientific Linux for use within their collaboration and SCCS has agreed to support it for the purpose of building BaBar software. This support will include running it on some batch build servers (i.e., the bldlnx* machines), on a cluster of interactive compute servers (the sl3-32 and sl4-32 load-balanced pools) and, on request, on BaBar desktop systems. However, RHEL remains the recommended Linux distribution at SLAC and will be the OS installed on the Linux batch farm and on most other Linux servers and desktops. BaBar has confirmed that its software can be built under SL 3 and the resulting binaries will run correctly under RHEL 3.

Other Linux Distributions

The following are explicitly not supported:

RHEL 2.x
Red Hat 9 or older
Fedora Core (any version)
Other Linux distributions (SUSE, Debian, etc.)

OS Updates

OS Release	minimum kernel	minimum glibc	recommended update level
RHEL 3	2.4.21-53.EL	2.3.2-95.50	RHEL 3u9
RHEL 4	2.6.9-67.0.4.EL	2.3.4-2.39	RHEL 4u6
SL 3	2.4.21-53.EL	2.3.2-95.50	SL 3.0.9
SL 4	2.6.9-67.0.4.EL	2.3.4-2.36	SL 4.5

All earlier versions of the kernel or glibc are explicitly prohibited.

Preparing to install Linux

Before Installation (and even purchase).
Recommended Hardware for Desktops and Laptops for Linux.
To get your Linux box properly installed follow the instructions below.
SCCS runs several large Linux clusters. Before you consider buying your own cluster, please contact us via unix-admin@slac.stanford.edu

Installation and Maintenance Procedures for Linux at SLAC

Once you have installed Linux on your system, we strongly recommend that you also install taylor, the SCCS tool for maintaining UNIX and Linux systems. Instructions for installing taylor are included with the OS installation instructions in the Web pages referenced above. Among other things, taylor will automate the process of regularly applying operating system updates.

Please note that if you cannot run taylor (e.g., because you are using some other Linux distribution), or do not choose to run it, you are still responsible for maintaining your system. This includes but is not limited to such things as:

regularly installing security patches
removing or disabling local accounts when users leave SLAC
guarding the root password
complying with DOE security regulations (e.g., displaying the security banner during login)
reporting suspicious activities to SCCS, etc.

For more information about the requirements for maintaining a non-taylored Linux system, please send mail to security@slac.stanford.edu.

Other Information

Join the SLAC Linux mailing list by sending mail to majordomo@slac.stanford.edu with the first line of body being subscribe linux-l
If you wish, SCCS will install Linux on a workstation that conforms to the "recommended hardware". You can talk to your local desktop administrator about this option or just submit this request form.
How to access Windows files: ICA Client Installation for Linux/Unix
Take a look at the new SLAC Linux FAQ.

Most of the following information is old and much of it is probably no longer relevant; use it at your own risk.

Pointers to some other SLAC sources of information about Linux
A list of other, non-SLAC Linux resources
BaBar needs some specific RPMs for their software; please see Required Software for BABAR Computing for their current requirements.
Frequently Asked Questions compiled by BaBar desktop support group.

Public Linux Machines at SLAC

SLAC provides several categories of public Linux machines.

A Linux batch farm with over a 1000 nodes (most dual processors) running the LSF batch management software.
Several load-balanced pools of machines for interactive, compute-intensive work. These machines have generic names reflecting the particular operating system on the machines in the pool, e.g., "rhel4-32" for a pool of machines running the 32-bit version of RHEL4.
A smaller load-balanced pool, generic name "iris", for light interactive work, e.g., reading email, editing, Web browsing.

For more complete information about these resources, please see the Public Machines at SLAC WEB page.

Len Moss