How to install Guest Additions for Ubuntu Guest in Virtualbox

Guest Additions are very useful in VirtualBox (or any other virtualization software in general), it installs virtual adapters for your hardware and enables the following:

• Better graphics support (very useful when resizing the desktop or changing the guest's resolution)
• Folder sharing between the host and the guest (you can refer to this article for a how-to)
• Mouse Integration

Maybe other features as well which I don't know. To install the guest addtions, you can simply follow the following five steps:

1. Click Devices->Install Guest Additions, this will mount a virtual cdrom containing the files from which we will install the guest addtions.
2. Open a terminal and navigate to the folder containing the guest additions "cd /media/cdrom"
3. Run the guest addition installer "sudo sh VBoxLinuxAdditions-x86.run"
4. Wait till the additions are installed and the kernel modules are compiled, note that this may take a few minutes.
5. Restart the Ubuntu guest.

This article is dedicated to my cousin Midoooz, to use it in his first virtual machine :)

How to solve the problems of "Oracle Enterprise Linux" in virtualbox

Not able to boot:
Just press escape during the grub loading process and choose the second kernel :), that's it! If you want it to be persistent to avoid doing that at every startup, just go edit the "/boot/grub/grub.conf" and change "default=0" to "default=1" to point to the second kernel automatically.

Source

Not able to install Guest Additions:

1. mount the installation DVD, navigate to the folder "Server" and issue the command "rpm -ivh kernel-devel-2.6.18-164.el5.i686.rpm"
2. unmount the DVD (if you're not able to unmount due to a bug in virtualbox that prevents unmounting, just shutdown the guest OS and then remove it from the storage section)
3. In the guest OS, click "Devices"->"Install Guest Additions"
4. The CD will be mounted, navigate to its folder (in /media/VBox***) and run "sh VBoxLinux***x86.sh" (x86 here if you're using 32-bit edition)
5. Reboot and enjoy :)