Installing Linux on a Second Hard Drive (two drives on the system):


If you want to install Linux on a second hard drive in your system, the process can be a little more complicated, depending on the distro that you choose. In this case, we will use Fedora as the example.


I don't want to install Linux on my main hard drive, as I am afraid I might mess up my xyz operating system.

You most likely came to this section, if you have more than one hard drive on your system and have decided to install Fedora on a second hard drive. In this case, you want to preserve the main hard drive which has Windows on it, or another operating system. This is fine, but some considerations must be made when choosing this option.

Fedora assumes that you  are installing on a single hard drive on your machine. Most users have only one hard drive, so this is by design. In this case, you must tell Fedora what you want to do, as it does not know, unless you tell it that this is your preference.


Figure 4.1

In this case, you will see more that one drive in the "Select the drive(s) to use for this installation. Drive hda will be you primary master drive (that you don't want to touch) and your second drive will be named according to where it is jumpered when you installed it. The naming scheme will be as follows;

hda = primary master drive
hdb = primary slave
hdc = secondary master
hdd = secondary slave

Remember, the drive order may not be in exact order, as you may have your second hard drive cabled on the primary interface, or the secondary one. So, if you cdrom drive is on the primary master, that drive will be hdb.

Obviously, you will uncheck hda, as you don't want to use this drive and make sure your second drive is checked for the installation.

Note that the default choice is to "Remove Linux partitions on selected drives and create default layout." This is fine if you have a previous installation of Linux and want to remove any  previous Linux partitions on the system, 

Use the option "Remove all partitions on selected drives and create default layout" if you want Fedora to "take over" the entire hard drive. Use this option with care. Doing so will remove all the partitions on the selected drive.

If you want Fedora to use empty (non-formated) space on the hard drive, choose the "Use free space on the selected drives and create default layout." The key here is non-formatted. This means free space not formatted with any filesystem at all, at the end of the drive.

Use the "create custom layout" if you want to tell Fedora to use pre-existing Linux partitions that you made on the hard drive. In this scenario, you need to know what you are doing.

For a more detailed explanation, see the Fedora Core 5 installation guide - partitioning section.

The important thing here, is that you want to modify grub, so that you can boot the system.


I installed Fedora and chose all the suggested default settings. Now my system does not boot, or goes straight into Windows when I boot the machine.

In a default Fedora installation on a second hard drive, Fedora assumes that that is the only drive in the system, unless you pick the advanced partition option when formatting the drive during the installation.

A boot directory on the drive is always made, which houses the vmlinux, initrd, config file, grub reference files and system.map file.  This does not mean that the bootloader itself was written to your boot drive and the system will boot from the primary master drive.

Even though you installed Grub to the MBR (Master Boot Record) the actual stage files reside on the hard drive in the Fedora install /boot directory. Only the part of grub that catches the MBR (the actual bootloader) resides on the MBR that directs things to the actual location of the grub stage files, menu.lst and device.map files.

If you choose to install the actual bootloader to the second drive (which is by default in your case when you installed Fedora), the MBR is written to the second drive.

Hence, this is why you booted right into Windows. The MBR of the actual boot drive (primary master) still had the bootloader for Windows only.


 OK, I understand this, but if  I change the boot order in the bios to my second drive (where the bootloader is), Fedora boots/does not, and the system just hangs when I try to boot Windows.

In terms of Windows, changing the boot order of the physical hard drives confuses the boot.ini file, which is set to look for the Windows start-up files on a specific drive. Changing the boot order in the bios changes the logical order of the drives, as seen by the bios. Now when Windows tries to boot, the boot.ini file looks for the Windows system files on the primary master drive (where Windows was originally installed), which is now your Fedora hard drive. The Windows system files and the boot.ini file is now your secondary hard drive. Windows is unable to boot.

Same thing with Fedora's grub is looking for the start-up files on the wrong drive. Grub tries to boot, but can't find the files it needs to complete the process. In this case, you know that Grub's bootloader is on the MBR of the drive where Fedora was installed on, not the MBR of your original primary master hard drive.

There is a workaround for this. See  Recovering Grub when you make a Mistake - Fedora on a second hard drive in the system.