CERN Private Cloud operating system images: SLC6/CC7/C8

CERN runs OpenStack Private Cloud infrastructure: for information please consult documentation

Available images

We provide images of CERN supported Linux versions:

CentOS 8 / x86_64
CERN CentOS 7 (CC7) / x86_64
Scientific Linux CERN 6 (SLC6) / x86_64 and / i686

these images can be selected for installation from OpenStack user interface while setting up your virtual system instance. Look for image names following this schema:

C8 TEST - x86_64 [YYY-MM-DD]
CC7 - x86_64 [YYYY-MM-DD]
SLC6 - x86_64 (/i686) [YYYY-MM-DD]

where YYYY-MM-DD correspond to year-month-day of release.

Images content

These images are provided as a base for further customization:

provide CERN standard preconfiguration for non-puppet managed installations.
contain rather minimal operating system installation.
use single root partition layout with default filesystem.
root filesystem is expanded to full disk capacity.
do not define swap partition.
automatically update installed packages.
both IPv4 and IPv6 is enabled using DHCP (availability depends on hypervisor configuration).
selinux is enabled.
firewall is enabled and opened for ports: 22/tcp (ssh), 7001/udp (afs3-callback), 4241/tcp (arcd / acrontab).
all standard updates yum repositories are enabled.
only command line tools are installed.
single image is provided for both puppet and non-puppet installations.

Images configuration

For installations to be managed by CERN Configuration Management (Puppet), please refer to documentation. (paragraph below does not apply to puppet managed systems)

Following is preconfigured on initial startup of the system from the image:

System update
Kerberos
AFS client
Sendmail
Root access with ssh key and kerberos for system owner (*)
AFS Accounts of owner(s) /main user(s) with sudo root access (*)
Printing to printers in owner(s) /main user(s) building(s)

(*) - according to information found in LanDB for the system.

System configuration and management

For installations to be managed by CERN Configuration Management (Puppet), please refer to documentation. (paragraph below does not apply to puppet managed systems)

Virtual systems installed from images can be managed same way as standard hardware ones. Please refer to SLC6, CC7, C8 documentation for details.

Converting image system to a CERN 'standard desktop' installation

SLC6 and CC7 systems offer a 'CERN Recommended Setup' installation option: a system installation with development tools and graphical user interface installed. Images can be easily converted to this kind of installation (but not including graphical user interface) by running:

# /usr/sbin/cern-recommended-setup install

If you wish to install including graphical user interface, please run:

# /usr/sbin/cern-recommended-setup install-desktop

Adding swap

If provided system memory is not enough for your application, you may add swapfile this way:

# dd if=/dev/zero of=/swapfile.001 bs=1M count=1024
# chmod 600 /swapfile.001
# mkswap /swapfile.001
# echo "/swapfile.001 swap swap defaults 0 0" >> /etc/fstab
# swapon -a

than verify that it is working correctly by running:

# free -m
              total        used        free      shared  buff/cache   available
Mem:           1829         320         104          27        1404        1276
Swap:          1023           0        1023

Known Problems

~~Not all user shells are installed by default. (addusercern will add user account without verifying this, making such account unuseable)~~

Images building information

Images are built using Koji CERN buildsystem. (Koji internally uses ImageFactory, Oz and libvirt with qemu-kvm running kickstart installations.)

Kickstart files used to create images can be found on CERN GitLab LinuxSupport Koji-Image-Build pages.

Support / Reporting problems

Please report problems to linux support @ CERN.

Linux @ CERN