RHN Satellite 5.7 satellite-sync timeout due to scanning proxy

If you're behind a scanning proxy, you might get these timeout errors with RHN Satellite: [cc] Exception in thread Thread-4: Traceback (most recent call last): File "/usr/lib64/python2.6/threading.py", line 532, in __bootstrap_inner self.run() File…

On Open Source and Security

We provide Linux and Open Source software consulting.  Sometimes, a potential client tells us "we don't use Open Source software because security is important for us". The proprietary industry has been spreading FUD claims on Open Source…

Scan logfiles: a Nagios PowerShell plugin

Let's imagine that you are using Nagios/Centreon to monitor your systems and you need an advanced tool to scan your logfiles. Your logfiles have a custom format timestamp and contain several fields, separated by spaces. You would like to…

RHEV / oVirt Python API VM creation script

Introduction In this post, we introduce vmcreate, our Python script for automating the creation of oVirt and RHEV virtual machines. This script has three purposes: to automate the creation of VMs with an easy to use command line interface …

RHEL6 auditing

If you want to monitor all actions on your servers, even those from root, there's a pretty straightforward and easy solution on RHEL6. Let's first analyze the different approaches: You can use pam_tty_audit to send all keystrokes to /var/log/audit/audit.log…

Puppet import loop when using directory environments

When switching to Puppet directory environments, you might get the following error: [cc lang="bash" nowrap="false"]Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Could not parse for environment production: Import…

LVM snapshots explained

This article explains how LVM snapshots work and what the advantage of read/write snapshots is. We will go through a simple example to illustrate our explanation. First, create a dummy device that we will initialize as a PV: [cc lang="bash"]#…

Virtual machines backup script for RHEV 3

Red Hat Enterprise Virtualization 3 (RHEV) comes with a great API that makes it easy to write Python scripts or Java programs for administrative tasks. The full documentation is available here : https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.3/html/Developer_Guide/index.html A…

What really happens during an RHN Satellite PXE boot ?

Debugging through the steps of an RHN Satellite or Spacewalk PXE boot and Kickstart is a pretty complicated task. This article shows the steps that are involved in such a boot process. Hopefully, this will clear up a little bit and help debugging…

Find the last modified file recursively

Let's say you're in /var/log and you want to find the last modified file. You'd type ls -lrt but this is not sufficient to find out which logfile was modified last, because that logifle might be hidden somewhere in a subdirectory. How do you…