A NethServer system is constituted by RPMs that come mainly from CentOS, EPEL and NethServer mirrors. Updates are announced by each project on its specific channel:

A NethServer machine fetches:

  • NethServer updates from an URL like:$releasever/updates/$basearch/
  • CentOS updates from an URL like:$releasever/updates/$basearch/
  • EPEL updates from an URL like:$basearch

Where $releasever is currently 7, and $basearch is x86_64.

All those packages updates improve the original system release by pushing it forward, like rolling continuously.

When CentOS produces a new minor version like 7.5.1804 they publish a new “minimal” ISO image. The NethServer developers add a small RPM set on that image together with a kickstart file. The resulting image is the NethServer ISO, with installer, server-manager and other stuff.

When NethServer 7.5.1804 is released, any existing 7.4.1708 installation can be upgraded seamlessly, because both CentOS and NethServer ensure compatibility between minor releases.

Locking to a specific distribution release


  • This procedure must be avoided in Subscription and Enterprise installations!
  • Human supervision of automatic updates is required in any case!

Sometimes you may need to lock the server to a specific release, like 7.4.1708. For instance, you enabled automatic updates but do not want to update automatically when a new CentOS/NethServer minor version is available.

  1. Ensure the nethserver-subscription RPM is installed. It is required because it ships the template configuration for /etc/yum/vars/nsrelease, that does not mean a Subscription is needed for this procedure to work:

    # yum install nethserver-subscription
  1. Select a CentOS mirror from the official mirror list, or run the command

    # yum --disablerepo=\* --enablerepo=updates repolist -v | grep ^Repo-baseurl

    The output is something like:

    Repo-baseurl :

    If the release is no more available from official mirrors, it has been probably moved to

  2. Copy the mirror prefix into a centosmirror YUM variable:

    # echo '' > /etc/yum/vars/centosmirror
  3. Add it to configuration backup:

    # echo /etc/yum/vars/centosmirror >> /etc/backup-config.d/custom.include
    # echo /etc/yum.repos.d/CentOS-Base.repo >> /etc/backup-config.d/custom.include
  4. Make a backup copy of the current CentOS repo file:

    # cp -a /etc/yum.repos.d/CentOS-Base.repo{,.bak}
  5. Configure CentOS repo to use the selected mirror:

    # sed -i 's/^mirrorlist=/#mirrorlist=/g; s|^#baseurl=$releasever|baseurl=$centosmirror/$nsrelease|g;' /etc/yum.repos.d/CentOS-Base.repo
  6. Create a template for the locked version number and expand it:

    # mkdir -p /etc/e-smith/templates-custom/etc/yum/vars/nsrelease/
    # echo '7.4.1708' > /etc/e-smith/templates-custom/etc/yum/vars/nsrelease/00version_lock
    # expand-template /etc/yum/vars/nsrelease
  7. Verify the repositories are configured correctly:

    # yum clean all && yum repolist -v

This procedure does not include the following upstream repositories, because they do not provide minor version paths, like 7.4.1708. They just provide 7, so a human supervision of the automatic updates is required in any case:

  • EPEL
  • SCL

To remove the release lock above run the commands:

# rm -f /etc/e-smith/templates-custom/etc/yum/vars/nsrelease/00version_lock
# expand-template /etc/yum/vars/nsrelease
# cp -a /etc/yum.repos.d/CentOS-Base.repo{.bak,}