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2. Choosing the Right Installation Medium


2.a. Hardware Requirements


Before we start, we first list what hardware requirements you need to successfully install Gentoo on your box.

The x86 architecture

2.b. Make your Choice


Still interested in trying out Gentoo? Well, then it is now time to choose the installation medium you want to use. Yes, you have the choice, no, they are not all equal, and yes, the result is always the same: a Gentoo base system.

The installation media we will describe are:

Every single media has its advantages and disadvantages. We will list the pros and cons of every medium so you have all the information to make a justified decision. But before we continue, let's explain our three-stage installation.

The Three Stages

Gentoo Linux can be installed using one of three stage tarball files. The one you choose depends on how much of the system you want to compile yourself. The stage1 tarball is used when you want to bootstrap and build the entire system from scratch. The stage2 tarball is used for building the entire system from a bootstrapped "semi-compiled" state. The stage3 tarball already contains a basic Gentoo Linux system that has been built for you. As we will explain later, you can also install Gentoo without compiling anything (except your kernel and some optional packages). If you want this, you have to use a stage3 tarball.

Now what stage do you have to choose?

Starting from a stage1 allows you to have total control over the optimization settings and optional build-time functionality that is initially enabled on your system. This makes stage1 installs good for power users who know what they are doing. It is also a great installation method for those who would like to know more about the inner workings of Gentoo Linux.

A stage1 installation can only be performed when you have a working Internet connection.

Stage1 Pros and Cons
+ Allows you to have total control over the optimization settings and optional build-time functionality that is initially enabled on your system
+ Suitable for powerusers that know what they are doing
+ Allows you to learn more about the inner workings of Gentoo
- Takes a long time to finish the installation
- If you don't intend to tweak the settings, it is probably a waste of time
- Not suitable for networkless installations

Stage2 installs allow you to skip the bootstrap process and doing this is fine if you are happy with the optimization settings that we chose for your particular stage2 tarball.

A stage2 installation can only be performed when you have a working Internet connection.

Stage2 Pros and Cons
+ You don't need to bootstrap
+ Faster than starting with stage1
+ You can still tweak your settings
- You cannot tweak as much as with a stage1
- It's not the fastest way to install Gentoo
- You have to accept the optimizations we chose for the bootstrap
- Not suitable for networkless installations

Choosing to go with a stage3 allows for the fastest install of Gentoo Linux, but also means that your base system will have the optimization settings that we chose for you (which to be honest, are good settings and were carefully chosen to enhance performance while maintaining stability). stage3 is also required if you want to install Gentoo using prebuilt packages or without a network connection.

Stage3 Pros and Cons
+ Fastest way to get a Gentoo base system
+ Suitable for networkless installations
- You cannot tweak the base system - it's built already
- You cannot brag about having used stage1 or stage2

You might be interested to know that, if you decide to use different optimization settings after having installed Gentoo, you will be able to recompile your entire system with the new optimization settings.

Now take a look at the available installation media.

Gentoo LiveCDs

The Gentoo LiveCDs are bootable CDs which contain a self-sustained Gentoo environment. They allow you to boot Linux from the CD. During the boot process your hardware is detected and the appropriate drivers are loaded. They are maintained by Gentoo developers.

All LiveCDs allow you to boot, setup networking, initialize your partitions and start installing Gentoo from the Internet. However, some LiveCDs also contain all necessary source code so you are able to install Gentoo without a working network configuration.

Now what do these LiveCDs contain?

Gentoo's Minimal LiveCD

This is a small, no-nonsense, bootable CD which sole purpose is to boot the system, prepare the networking and continue with the Gentoo installation. It does not contain any stages (or, in some cases, a single stage1 file), source code or precompiled packages. For example the x86 variant of this LiveCD can be found in the universal subdirectory and is called install-x86-minimal-2004.2.iso.

Minimal LiveCD Pros and Cons
+ Smallest download
+ Suitable for a complete architecture
+ You can do a stage1, stage2 or stage3 by getting the stage tarball off the net
- Contains no stages, no portage snapshot, no GRP packages and therefore not suitable for networkless installation

Gentoo's Universal LiveCD

Gentoo's Universal LiveCD is a bootable CD suitable to install Gentoo without networking. It contains a stage1 and several stage3 tarballs (optimized for the individual subarchitectures). For example the x86 variant of this CD is called install-x86-universal-2004.2.iso and can be found in the universal subdirectory.

If you take a closer look into releases/x86/2004.2 you will see that we also provide Gentoo Package CDs (in the packagecd/) directory. This CD (which isn't bootable) only contains precompiled packages and can be used to install software after a succesfull Gentoo Installation. To install Gentoo, you only need the Universal LiveCD, but if you want OpenOffice.org, Mozilla, KDE, GNOME etc. without having to compile every single one of them, you need the Packages CD too. For example the i686 (a subarchitecture of x86) Packages CD is called packages-i686-2004.2.iso and can be found in the appropriate subdirectory (i686).

You only need the Packages CD if you want to perform a stage3 with GRP installation.

Universal LiveCD with Packages CD Pros and Cons
+ Packages CD is optimized to your subarchitecture
+ Packages CD provides precompiled packages for fast Gentoo installations
+ Contains everything you need. You can even install without a network connection.
- Huge download

2.c. Download, Burn and Boot a Gentoo LiveCD

Downloading and Burning the LiveCDs

You have chosen to use a Gentoo LiveCD. We'll first start by downloading and burning the chosen LiveCD. We previously discussed the several available LiveCDs, but where can you find them?

You can download any of the LiveCDs (and, if you want, also a Packages CD) from one of our mirrors. The LiveCDs are located in the releases/x86/2004.2/livecd directory; the Packages CDs are located in the releases/x86/2004.2/packagecd directory.

Inside that directory you'll find so-called ISO-files. Those are full CD images which you can write on a CD-R.

In case you wonder if your downloaded file is corrupted or not, you can check its MD5 checksum and compare it with the MD5 checksum we provide (such as install-x86-minimal-2004.2.iso.md5). You can check the MD5 checksum with the md5sum tool under Linux/Unix or md5sum for Windows.

To burn the downloaded ISO(s), you have to select raw-burning. How you do this is highly program-dependent. We will discuss cdrecord and K3B here; more information can be found in our Gentoo FAQ.

Booting the LiveCD(s)

Important: Read this whole subsection before continuing, as you will not always have the time to read before acting.

Once you have burned your installation CDs, it is time to boot them. Remove all CDs from your CD drives, reboot your system and enter the BIOS. This is usually done by hitting DEL, F1 or ESC, depending on your BIOS. Inside the BIOS, change the boot order so that the CD-ROM is tried before the hard disk. This is often found under "CMOS Setup". If you don't do this, your system will just reboot from the hard disk, ignoring the CD-ROM.

Now place the installation CD in the CD-ROM drive (duh) and reboot. You should see a fancy boot screen with the Gentoo Linux logo on it. At this screen, you can hit Enter to begin the boot process with the default boot options, or boot the LiveCD with custom boot options by specifying a kernel followed by boot options and then hitting Enter.

Specifying a kernel? Yes, we provide several kernels on our LiveCDs. The default one is gentoo. Other kernels are smp, which activates support for multi-cpu systems and the -nofb variants which disable framebuffer.

Below you'll find a short overview on the available kernels:

Kernel Description
gentoo Default 2.4 kernel with framebuffer support
smp 2.6 Kernel with support for multiple CPUs
gentoo-nofb Same as gentoo but without framebuffer support
smp-nofb Same as smp but without framebuffer support
memtest86 Test your local RAM for errors

You can also provide kernel options. They represent optional settings you can (de)activate at will. The following list is the same one you receive when you press F2 at the bootscreen.

Code listing 1: Options available to pass to your kernel of choice

- agpgart       loads agpgart (use if you have graphic problems,lockups)
- doscsi        scan for scsi devices (breaks some ethernet cards)
- nodetect      causes hwsetup/kudzu and hotplug not to run
- dofirewire    modprobes firewire modules in initrd (for firewire cdroms,etc)
- nousb         disables usb module load from initrd, disables hotplug
- nodhcp        dhcp does not automatically start if nic detected
- doataraid     loads ide raid modules from initrd
- dopcmcia      starts pcmcia service
- noapm         disables apm module load
- noraid        disables loading of evms modules
- nohotplug     disables loading hotplug service
- ide=nodma     Force disabling of dma for malfunctioning ide devices
- docache       Cache the entire runtime portion of cd in ram, allows you
                to umount /mnt/cdrom to mount another cdrom.
- dokeymap      enable keymap selection for non-us keyboard layouts
- noapic        disable apic (try if having hardware problems ,nics,scsi,etc)
- hdx=stroke    (smp/smp-nofb kernel only) Allows you to partition the whole
                harddrive even if your BIOS can't handle large harddrive

Now boot your CD, select a kernel (if you are not happy with the default gentoo kernel) and boot options. As an example, we show you how to boot the gentoo kernel, with dopcmcia as kernel parameters:

Code listing 2: Booting a LiveCD

boot: gentoo dopcmcia

You will then be greeted with another boot screen and progress bar. Once the boot process completes, you will be automatically logged in to the "Live" Gentoo Linux as "root", the super user. You should have a root ("#") prompt on the current console and can also switch to other consoles by pressing Alt-F2, Alt-F3 and Alt-F4. Get back to the one you started on by pressing Alt-F1.

If you are installing Gentoo on a system with a non-US keyboard, make sure you boot the LiveCD with the dokeymap boot option.

Now continue with Extra Hardware Configuration.

Extra Hardware Configuration

When the Live CD boots, it tries to detect all your hardware devices and loads the appropriate kernel modules to support your hardware. In the vast majority of cases, it does a very good job. However, in some cases (the SPARC LiveCDs don't even do autodetection), it may not auto-load the kernel modules you need. If the PCI auto-detection missed some of your system's hardware, you will have to load the appropriate kernel modules manually.

In the next example we try to load the 8139too module (support for certain kinds of network interfaces):

Code listing 3: Loading kernel modules

# modprobe 8139too

Optional: Tweaking Hard Disk Performance

If you are an advanced user, you might want to tweak the IDE hard disk performance using hdparm. With the -tT options you can test the performance of your disk (execute it several times to get a more precise impression):

Code listing 4: Testing disk performance

# hdparm -tT /dev/hda

To tweak, you can use any of the following examples (or experiment yourself) which use /dev/hda as disk (substitute with your disk):

Code listing 5: Tweaking hard disk performance

Activate DMA:                                       # hdparm -d 1 /dev/hda
Activate DMA + Safe Performance-enhancing Options:  # hdparm -d 1 -A 1 -m 16 -u 1 -a 64 /dev/hda

Optional: User Accounts

If you plan on giving other people access to your installation environment or you want to chat using irssi without root privileges (for security reasons), you need to create the necessary user accounts and change the root password.

To change the root password, use the passwd utility:

Code listing 6: Changing the root password

# passwd
New password: (Enter your new password)
Re-enter password: (Re-enter your password)

To create a user account, we first enter their credentials, followed by its password. We use useradd and passwd for these tasks. In the next example, we create a user called "john".

Code listing 7: Creating a user account

# useradd john
# passwd john
New password: (Enter john's password)
Re-enter password: (Re-enter john's password)

You can change your user id from root to the newly created user by using su:

Code listing 8: Changing user id

# su john -

Optional: Starting the SSH Daemon

If you want to allow other users to access your computer during the Gentoo installation (perhaps because those users are going to help you install Gentoo, or even do it for you), you need to create a user account for them and perhaps even provide them with your root password (only do that if you fully trust that user).

To fire up the SSH daemon, execute the following command:

Code listing 9: Starting the SSH daemon

# /etc/init.d/sshd start

To be able to use sshd, you first need to setup your networking. Continue with the chapter on Configuring your Network.

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