SLAC National Accelerator Laboratory
Computing Division

End of Support for RHEL4 and SL4

SLAC Computing
Linux at SLAC
Updated: 26 Oct 2011

Vendor support for Red Hat Enterprise Linux 4 (RHEL4) and Scientific Linux 4 (SL4) is scheduled to end in February 2012 (29 Feb 2012 for RHEL4 and 2 Feb 2012 for SL4). After those dates there will be no further security patches for these Linux distributions.

SLAC's Computing Division has set a goal of either upgrading or retiring as many RHEL4 and SL4 machines as possible by 9 Dec 2011. To achieve this goal we are taking the following steps.

New Installs

Effective immediately, we are imposing a moratorium on new installations of RHEL4 or SL4.


Users of RHEL4 and SL4 desktop systems should be contacted in the near future by their IT Departmental Support person to schedule an upgrade to a newer release of RHEL or to retire the system as soon as possible.

Public Machines

There are currently several pools of RHEL4 and SL4 machines available for public login:

Pool namesOS
"rhel4-32", "rhel4-32-test" 32-bit RHEL4
"rhel4-64", "rhel4-64-test" 64-bit RHEL4
"sl4-32", "sl4-32-test" 32-bit SL4

In the near future we will limit access to these systems (see below).

Batch Machines

The only RHEL4/SL4 resources in the public batch farm are three batch build machines:

Server nameOS
bldlnx01 32-bit SL4
bldlnx02 32-bit SL4
bldlnx09 64-bit RHEL4

In the near future we will limit access to these systems (see below).

We will work with the owners of private RHEL4 batch clusters to either upgrade or retire their systems.


There are a number of other RHEL4/SL4 servers currently in use. We will be contacting the users responsible for these servers to plan for their upgrade or retirement.

15 Nov 2011 - Restricted access to RHEL4/SL4 public login and batch build machines

On Tuesday morning, 15 Nov, we will restrict access to the following pools of public machines:

  • "rhel4-32" and "rhel4-32-test"
  • "rhel4-64" and "rhel4-64-test"
  • "sl4-32" and "sl4-32-test"

Current users of these pools should begin using one of the other pools of public interactive compute servers:

Pool namesOS
"rhel6-32", "rhel6-32-test" 32-bit RHEL6
"rhel6-64", "rhel6-64-test" 64-bit RHEL6
"rhel5-32" (aka "noric", "yakut"),
32-bit RHEL5
"rhel5-64", "rhel5-64-test" 64-bit RHEL5

Also on Tuesday, 15 Nov, we will restrict access to the RHEL4/SL4 batch build machines:

  • bldlnx01 (32-bit SL4)
  • bldlnx02 (32-bit SL4)
  • bldlnx09 (64-bit RHEL4)

The LSF batch queue "bld4q" has been established to allow a restricted group of users to run RHEL4/SL4 build jobs. These servers have been removed from all other "build" queues.

If you believe you will have a critical dependence on one of these RHEL4/SL4 login pools or batch build systems after 15 Nov, please send an email to explaining:

  1. which pool(s) or build machine(s) you need to access;
  2. why you need access; and
  3. how you plan to eliminate this dependency by the 9 December 2011 target date.

9 Dec 2011 - SLAC target for eliminating RHEL4/SL4

16 Dec 2011 - Last day before SLAC Winter Closure

2 Feb 2012 - Vendor EOL for Scientific Linux 4

29 Feb 2012 - Vendor EOL for Red Hat Enterprise Linux 4

Len Moss