First, figure out which VMs you have on your machine.

haddad-work:~ jhaddad$ VBoxManage list vms
Oracle VM VirtualBox Command Line Management Interface Version 3.2.6
(C) 2005-2010 Oracle Corporation
All rights reserved.

"WebServer" {2c61a180-e098-4926-b09a-27e431791c88}

Then start it using VBoxHeadless

nohup VBoxHeadless -s WebServer -vrdp on  &

I’m using Cord for RDP.

Open up Cord. If you’re using the default settings, you can just go to quick connect and type “localhost”. You’ll see your VM booting.

yum install -y gcc kernel-devel-`uname -r`
mkdir /mnt/cdrom
mount -o ro -t iso9660 /dev/cdrom /mnt/cdrom
sh /mnt/cdrom/VBoxLinuxAdditions-amd64.run

Info found on tuxtraining.com

Virtualization is now a commodity with several free tools available from Sun, VMWare and Xen. If you’re like me, you like to create a new, clean VM for each experiment. However, this comes with a drawback – the installation process, choosing your timezone, putting in the same password every time, etc… takes a while.

Fortunately, CentOS provides the means to automate the process via a kickstart file. The best part is, after you do an install, you’ll have a kickstart file to start working with – it’ll save all your options in /root/anaconda-ks.cfg. You can edit this file later to include other packages that you’d like to install, such as the GCC c++ libraries. You can also run other commands through yum, and customize the system-wide bashrc.

I’m only going to go over how I did the install – for the full details check out the CentOS kickstart guide

I’ve created a minimal kickstart file to do a base install without gnome, printing, and any tools I don’t find useful. I’ve disabled X completely – I have no need to boot to a GUI. I’ve also uncommented the lines to configure the drive settings, so I won’t be prompted for anything along the way; my VM should be completely ready to go once I reboot after the installation. Pretty awesome.

There’s a convenient way to run a kickstart file off a http connection, so I’ve put it the web server on my dev box. My dev box’s IP address is 192.168.1.5, and I copied the modified /root/anaconda-ds.cnf (which I’ve renamed to ks.cfg) to the server. At the installation boot prompt, I’d enter:

linux ks=http://192.168.1.5/ks.cfg

Then let it run. After a bit it’ll ready to reboot and be used. Just make sure to unmount the install DVD.

Obviously this has a lot more uses than just creating VMs, but I’m not a sysadmin, so I haven’t personally used it outside the desktop environment. There’s other tools for different distros, and third party tools for CentOS/RedHat.

For what I’ve done so far, one could argue it’s easier just to create an image of the VM and to just clone that whenever I want a new one. That’s a good solution if I was interested in always creating the same exact VM. However, using the kickstart method has several advantages. I could create a simple web app that generates new configs based on what I’ve checked off in a few lists, allowing me to quickly fire up new VMs with the right software for whatever I’m working on. I can also upgrade the version of the OS and run the same kickstart, so I don’t have to maintain some up to date starting image.

If I’ve made any mistakes, please don’t hesitate to point them out. I’m by no means a guru on the subject, I’ve just wanted to look into this topic for a while.

Some Other Useful resources

• Linux-Mag
• Red Hat Kickstart Guide

When creating a new VM through VirtualBox, you might have a problem SSH’ing into the box. You also might notice you get a 10.0.x.xx type address, even though the rest of your network is a 192.168.xx.xxx deal. Yes, the two are related.

Essentially what’s happening is the VM is sitting on it’s on little private line, where it can go out but nothing can reach it. By default, the network setting is “NAT”. If we want the VM to be accessible to the outside, we want to use Bridged networking.

This is easily solved, but requires that the VM be shut down. Go to the network second, pick an unused adapter (likely the 2nd one), enable it, and choose Bridged.

You should see this under the VM description now.

Go ahead and boot back into your VM. Fire up a terminal, run /sbin/ifconfig, and you’ll see you now have an ethernet adapter with an address you can reach.

Enjoy!