PXE boot a virtual machine with NAT connection to the host

If you have a notebook and you want to quickly deploy new virtual machines for testing, PXE boot is your friend. On notebooks people are usally not using a bridged network but NAT instead. The DHCP server on the host that is managed by Libvirt needs to configured with the TFTP server and the boot file. On my “mobile lab”, I’ve installed a virtual machine with a Redhat Satellite 5 where the other VMs get its content from. PXE boot ….Read More

Automated disk partitioning on virtual machines with Cobbler

The default Cobbler Snippets just do simple auto partitioning. For a more sophisticated partition layout you need to know what kind of VM you are going to install. KVMs and RHEVs device name is /dev/vda, Xen uses /dev/xvda and ESX /dev/sda. Luckily this can be figured out automatically, those different virtualization vendors are using its own MAC prefixes. So we can add two nice small Cobbler snippets to do the job. In this example, I call them hw-detect and partitioning. ….Read More

Implement a high available Cobbler provisioning system

A not so well known feature of Cobbler is its replication facility. It allows you to create a high available system provisioning system. The whole set up is straight forward. Background Today people tend to NOT backup systems, only data is being backed up. In the case of a system failure, they just re-provisioning the system and automatically configure it with configuration management tools such as Puppet, CFengine or RHN Satellite. You not only need to have your configuration management ….Read More

Updating a distro in cobbler

A few weeks ago RHEL 5.6 was released, the installation media was also updated. So it is time to get it into cobbler to deploy the latest dot release when provisioning new systems. Lets assume your profile name is rhel5-x86_64, you have an existing distro named rhel55-x86_64 and you want to replace it with rhel56-x86_64. Lets start with importing the new distro: # Mount the ISO as loop back mount /some/where/rhel-server-5.6-x86_64-dvd.iso /mnt/rhel56iso -o loop # Import the Install Media cobbler ….Read More

Deploying RHEL as ESX guests – Kickstarting or using ESX templates?

Some time ago I asked my self the question if it is better to kickstart systems or working with ESX templates when deploying RHEL as ESX guests. I also had some discussions with friends working in the same industry. I tried it and came to the following conclusion: Kickstart the systems is the way to go. Pros: Kickstarted Systems are already up-to-date after installation. Proper SSH host keys. Using ESX templates ends up in having identical SSH host keys, from ….Read More