Clean Up And Modify he new Ubuntu Grub2 boot menu differs quite a bit from the previous version. As Ubuntu nominated the new version 2 of the Grub boot manager as of 9.10, removing of the old problematic menu.lst file.

Ubuntu Grub2 Boot Menu

Grub2 is a leap forward in many ways, and most of the annoyances from menu.lst are gone. Yet, if you don’t clean up old versions of kernel entries, the boot list can quickly get messy and end up in a long list of nonsense. Let’s assume we want to remove the 2.6.32-21-generic boot menu entries. Previously, this meant editing /boot/grub/menu.lst. But with Grub2, we use the package manager to remove the kernel package from our computer, Grub automatically removes those options. Btw. if only one operating system is installed on your computer, you may not see the boot menu at all and have to hold down the SHIFT button on your keyboard while booting up to get the menu to show.

To remove old kernel versions, open up Synaptic Package Manager, found in the System > Administration menu. When Synaptic opens up, type the kernel version that you want to remove into the Quick search text field. The first few numbers should suffice. Then for each of the entries associated with the outdated kernel (e.g. linux-headers-2.6.32-21 and linux-image-2.6.32-21-generic), right-click and choose “Mark for Complete Removal”, then hit “Apply”. These entries will be gone upon the next boot.

If you like more control, or add/remove entries that are not kernel related, you can change the file grub.d located in /etc. This file contains files that hold menu entries that used to be located in /boot/grub/menu.lst. If you want to add new boot menu entries, you simply create a new file in this folder, ensure it is executable (chmod +x).

Another way to remove boot menu entries without deleting the files is to remove execute flag (chmod -x). With any change to these files, we need Grub to update it’s database: sudo update-grub.

For more information on Grub2, it’s inner workings and differences to it’s older sibling, check out Ubuntu Grub2 Wiki

Forgot your root password? Nice going. What now? Reinstall the machine from ground up? Sadly enough, I’ve seen this happening all too often while it’s surprisingly easy to change the password knowing the correct procedure. While this doesn’t work in all cases (like if you secured your machine with a GRUB password and forgot that as well), but here’s the procedure in case of a CentOS Linux machine.

Start off by rebooting your system. At the GRUB boot loader screen, move the highlighted entry with the arrow keys to interrupt the boot process. While the current boot entry is highlighted, press E and you can edit the kernel line.

Grub boot loader screen

Use the arrow key to highlight the line that starts with kernel, and press E to edit the kernel parameters. When you get to the screen below, append the number 1 at the end of the line. This will enable you to boot into single-user mode.

Edit GRUB boot loader entry

Next press Enter, then B, and the kernel will boot up into single-user mode. Once there you can run the passwd command, changing the password for user root:

prod-093# passwd
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully

Next time you boot up, use your newly created password to login.

…with Windows Vista / Windows 7 installed first.

So you got a computer running Vista and like to dual boot between Vista and Ubuntu. The boot loader that ships with Vista can be a real pain. There are some nice utilities we can use to make that process a lot smoother for us. Here we go.

First you’ll need space for the Ubuntu installation. If you don’t already have a partition for it, right-click My Computer -> Manage -> Disk Management. Right-click on the main Vista partition and select Shrink Volume. The Shrink tool will assess how much space you can free up. (If you don’t have enough free space, Vista will not allow you to shrink it and the available space to shrink will be zero) You should have at least 12GB of free space for the new OS, if you don’t have that much it’s probably time for a new hard drive.

Next step is to prepare your installation USB drive, unless you already burned it on a CD/DVD. Follow our detailed instructions in this article. Insert the usb stick, or the CD/DVD and reboot. Check you system for booting from USB, usually you have to press a function key to select from possible boot media.

Follow the standard installation instruction during the Ubuntu install, choosing the newly created partition as target. You also can import accounts and personal folders from Vista, if the Ubuntu installer detects it. Everything else should be pretty straight forward. Once the installation is finished, let the system reboot and you will have a boot menu with listings for Ubuntu and Vista.

So far, all should be well and you can boot to Vista or Ubuntu using GRUB. Unless you want Vista to be in charge of the boot process, you’re done. The next step will explain how to revert back to the Vista boot loader and add Ubuntu as a choice of OS.

Boot to Ubuntu and copy the contents of the boot menu so that it is available in Vista. Open a terminal (Applications -> Accessories -> Terminal). Then open menu.lst (sudo gedit /boot/grub/menu.lst) and copy/paste it into a text document and save it onto the Vista partition. Alternatively you can send it by email or save it onto the USB memory stick. Then reboot into Vista.

Now we need the latest version of EasyBCD by Neosmart Technologies - download it here and install. Then, go to “Manage Bootloader” and select “Reinstall the Vista Bootloader”, then “Write MBR”.

This puts the Vista bootloader back into the MBR, but the machine will only boot into Vista at this time.To enable access to the Linux partition, the best option is to install NeoGrub. Go to “Add/Remove Entries”, go to the NeoGrub tab and select “Install NeoGrub”. This adds the “NeoGrub Bootloader” option to the Vista bootloader. Then choose Configure – this launches the NeoGrub menu.lst file, location at C:\NST\menu.lst. Use Notepad or Wordpad to open the file, and then paste in the boot entries that we copied from Ubuntu.

Save and exit, then reboot the machine. The system will come up with two boot options. Select “NeoGrub Bootloader” and then the Linux boot options will load. Choose the relevant option and the system boots into Ubuntu.

I rarely do upgrades and try to avoid them whenever possible, instead do always fresh installs as I like to do  house-cleaning when upgrading to a new version of OS. As I have a separate /home partition, this doesn’t affect any of my settings and only takes 1-2 hours (less than one hour on a high speed Internet connection),  which is comparable to the upgrade option from within 7.xx.

What is UNetbootin?
UNetbootin creates a boot option in GRUB or the Windows bootloader that will download the installation files directly over the Internet and starts the installation. I find this very attractive since I don’t have to download or burn any CD’s. It works from within Windows and Linux and a variety of distro’s can be installed this way besides Ubuntu. The process is more than ideal with the new generation of netbooks, like the Dell mini, Asus EEE just to name a few, which don’t have optical drives.

Installation

1. Let’s first install the dependencies required by UNetbootin:

aptitude install ms-sys syslinux p7zip-full libqt4-gui

2. Download UNetbootin from here.

3. Make the downloaded file executable and run the install (you may need administrative rights):

chmod +x unetbootin-linux-319

./unetbootin-linux-319

4. You should now have a window like below. Select your distro and whether to use a disk or USB stick. Very convenient that you can simply choose an ISO, in case you want to download the distro first and then get it on the USB stick. Make sure to select “Disk Image” if that is what you want.

5. After hitting ok, the installation files will be downloaded over the internet.

6. Finally you are asked to reboot and start the Ubuntu installation process.

7. During the reboot, you will now have an option “unetbootin” to boot into. After that, simply follow the standard installation process.

Unetbootin is really a life saver. Gone are the ages where we needed to burn CD’s for OS installations. And the speed at which the installer races thru is just amazing. Mine literally took like 10 minutes!