With FirewallD, some Linux distributions introduce a new default firewall differing heavily from previous interfaces. This post focusses the basic concept and some practical examples.

A major difference is that the firewall now supports changes in realtime without dropping active connections. FirewallD integrates …

Recently I had some issues with a Linux cluster running Corosync, Pacemaker and Apache. I was unable to run the redskin as ressource - starting always failed with "invalid parameter":

 1# crm resource start apache
 2# crm status
 3...
 42 nodes configured
 55 resources configured
 6
 7Online: [ deb9-node2 …

A fresh Spacewalk installation usually defines user accounts in a local manner - including permissions. Especially for bigger system landscapes with requirements such as Single Sign-on, this is not a practical solution.

Fortunately, Spacewalk and Red Hat Satellite 5 support authentication using FreeIPA and Red Hat …

Every Linux user knows the following scenario: a running process should be moved to another terminal. An example: an application update takes longer than expected and the status should be monitored on the go in GNU Screen. It's just nasty, if you forgot to prepare this prior to that.

Happily, there are plenty tools for …

To find out the WWN port name of a HBA under Linux, reading the port_name file is sufficient - e.g. for all HBAs:

1$ cat /sys/class/scsi_host/host*/device/fc_host/host*/port_name
20x2002f6dc44b8e2b6
30x2001f6dc44b8e2b6

After a system crash I recently had the problem that Foreman had several orphaned tasks that could not be stopped from the web interface:

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  loading="lazy"
  decoding="async"
  alt="Hängende Aufgabe" …</picture></figure></p>

I'm currently working on a blog post series about Foreman, Katello and Red Hat Satellite 6.

Here's the link collection for beginners:

1. "Introduction and installation" (also published on Pro-Linux [button size="xsmall" color="red"]german[/button])
2. "Products, Repositories and Content …

Currently I'm spending a lot of time on automating complex application scenarios; during training I also starting learning about creating customized REST applications. The result was a tutorial which covers all stages of developing a small "RESTful" application:

1. Concept/Definition
2. Development
3. Tests and …

GitLab can utilize LDAP to authenticate against a variety of directory services such as Microsoft Active Directory Domain Services or FreeIPA and Red Hat Identity Management. This post describes configuring and integrating into FreeIPA.

By clicking Identity > User Groups > Add within the FreeIPA interface, an …