End of general user support for Scientific Linux CERN 4 (SLC4) - 31st of December 2010

Linux @ CERN

CERN > IT > OIS > Linux

Before you start
  • Check that your machine is properly registered on the CERN network

  • Check that CERN Domain Name Service is updated for your machine:
      host yourmachine command should return an answer.

  • If the system you are installing on is one of CERN standard types: Please check for hardware-specific instructions.

  • Check that your machine meets minimum system requirements
    • Memory: Minimum 256 MB (system will run with less but performance may be affected)
    • Processor: 300 Mhz i686 / athlon (or compatible)
    • Disk space: 6 GB (including 1 GB user data) for default setup ( 1 GB for customized setup)

    • For Athlon 64/Opteron/Intel with EM64T and Itanium 2 systems minimum memory requirement is 512 MB.

  • New!: Please see our media-less installation procedure at: Linux Installation, if you use it you may skip following points up to system installation.

  • Prepare boot media (you will need a single recordable CD or USB memory key). Check the Boot Media preparation page for instructions how to prepare (and check) your boot media.
    • Available Boot Media:
      • Boot CD (boot.iso)
      • USB pen drive Boot image (diskboot.img)
      • For machines already running an older version of CERN Linux: kickstart-me is a small utility that copies the equivalent of the Boot CD to a local harddisk, and makes reinstallation a boot-time option.
        Run (as root):
        /afs/cern.ch/project/linux/redhat/kickstart/bin/kickstart-me slc4X
        and reboot, select "Reinstallation"

    • For Athlon 64/Opteron/Intel with EM64T and Itanium 2 systems:

  • Following installation methods are supported:
    • NFS - the default one.
    • http
    • ftp
    (Please note: If your machine is located outside of CERN network ONLY http install method will work.)

  • The installation server is:
    • linuxsoft.cern.ch

  • The installation path for above methods is:
    • /cern/slc4X/i386/
    • (/cern/slc4X/ia64 for Itanium 2)
    • (/cern/slc4X/x86_64 for Opteron)

  
 

System installation
Linux installation prompt
Installation language selection
Keyboard selection
Installation method selection
Network configuration
Please note: IT-CS is providing a DHCP service even for machines with a static IP address, under the condition that the MAC (network card) address is correctly registered in LanDB. This allows you to leave the setting for the network configuration on "DHCP" for desktop machines.
If you set a hostname manually, please make sure it includes a domain. E.g. mymachine will cause trouble, mymachine.mydomain is OK (even if not very original). If you use cern.ch as domain, please use the correct hostname as registered in LanDB - this will otherwise cause support grief...
Specification of the Linux installation image location. The default values should be OK.


Please note: Upgrade from previous SLC versions is NOT SUPPORTED.
We advise you to select the default option called CERN Recommended Setup This preset configuration requires about 4000 MB of disk space for the system and all preselected tools.
Automatic partioning option will preallocate separate /boot [ /boot/efi on ia64 ] and / partitions (/boot of 128 or 256 MB, / will expand for the rest of available disk space).
Please note that automatic partitioning option will suggest to remove all pre-existing disk partitions of Linux type.
Please review the proposed partitioning schema and make needed changes.


Please note: Default firewall setup opens it only for ssh and afs client. Do not disable the afs client firewall setting or your AFS access will not work.
We recommend leaving default system language as it is preset: US English (Otherwise you may experience problems with different CERN environment scripts which have not been ported to SLC3 at this time)

Please note that AFS user accounts should be added after installation and reboot using ccdbuser addusercern command.
On this installation screen you may change the default preselection of package groups and individual packages. We recommend however to leave the preselection as it is defined, to ensure the compatibility of your system with others (and future CERN central services running SLC3). Packages selection can be easily altered on the installed system.
Please note that installing "Everything" is discouraged, this will install literally all available packages (including those which don't make sense in the CERN environment) and will have you running a lot of services that are typically not needed.

This installation step indeed takes minutes on a quite modern machine: If your system is an older one this may take up to ten minutes...
For next 25-50 minutes your system will be installing over the network, showing installation progress.

That's it ... remove your boot media and the machine restarts to complete the setup process.
 

Firstboot integrated post-install configuration adjustment
If your graphic setup was autoconfigured properly on first system boot screens you will be presented with following screens which will allow you to customize your system for use in CERN computing environment.


Date & Time setup screen allows setting of system date and clock.
Please note: We recommend to select the network time protocol (NTP) tab described below. Otherwise AFS authentication will fail once the machine clock has drifted (and PC clocks are not very precise).
... and select one or more of CERN time servers from the list.
Display configuration allows for setting up suitable graphics environment parameters.
Please note: Some older monitors may not be detected automatically, please make sure to select values within the monitor operating range !
Sound card screen allows testing of the audio device.
CERN customization screen will allow you to setup your system updates mode and whether AFS client should start on system boot. Also site configuration defaults will be applied for Kerberos 4, Zephyr ... etc setup
Please note: We recommend to accept default settings which should be correct for most of CERN users, these settings can be easily changed afterwards.


 

Logging in

After the first boot setup ends you will be presented with graphical login prompt, allowing the choice of session language and type. After choosing ...
... KDE
... or GNOME
session will start.

Note: languages in the session screenshots above are just examples, default system language is set to English.
 

Manual post-install configuration adjustment
If you have selected not to run X graphical environment on your machine , or you have installed system using kickstart and you want to apply site configuration settings, here is a short recipe:
  • AFS client
    • Run /usr/sbin/lcm --configure afsclt to preconfigure AFS client for CERN site (and AFS logins)
    • Add client to system startup: /sbin/chkconfig --add afs
    • Start the client: /sbin/service afs start
  • Automatic update system (can also be set for machines outside CERN network)
      Edit /etc/sysconfig/yum-autoupdate and set:
    • YUMUPDATE=0 to be informed about available updates (by e-mail to root)
    • YUMUPDATE=1 for the automatic updates to be applied
      Next configure and start automatic update system:
    • /sbin/chkconfig --add yum-autoupdate
    • /sbin/service yum-autoupdate start
  • Apply CERN site configuration defaults
    • run /usr/sbin/lcm --configure srvtab (please note that in order to do so you need to run AFS client setup for CERN)
    • run /usr/sbin/lcm --configure krb4clt krb5clt sendmail zephyrclt pine security to setup other available defaults
      •    You can use /usr/sbin/lcm --list to see all configuration backends installed on your machine.
  • Check currently running/enabled services
    • via /sbin/chkconfig --list
    • turn off those services you don't need via /sbin/chkconfig servicename off; /sbin/service servicename stop
    • turn on other services (once you configured them) via /sbin/chkconfig servicename on,
      one important service would be ntpd if you have AFS accounts (configure CERN Time servers in /etc/ntp.conf and /etc/ntp/step-tickers).
      To immediately start the service (chkconfig just turns it on for the next reboot), use /sbin/service servicename start
 

Creating AFS user accounts
After the successfull installation and initial configuration of the system AFS user accounts can be added using following command sequence, as root:
  • /usr/sbin/ccdbuser /usr/sbin/addusercern username (Your own AFS username can be obtained by running phonebook --all yourname command)
  • in case there is an issue running this command (AFS/ORACLE/CCDB/CRA/.. trouble), the matching account line can also be cut&pasted from e.g. LXPLUS's /etc/passwd file into the local /etc/passwd
  • (on IA64, you may need to run LD_ASSUME_KERNEL=2.4 ccdbuser username, thanks to the use of an i386 binary there)i

Applying software updates
You should update your system immediately after it's installation: Eventual security errata and bug fixes will be applied this way before you start using it.

As root run: 
 # /usr/bin/yum -y update
to apply all available updates.

For more information about system updates please check Software Management page.
For more information about system configuration please check Configuration Management page.