Installation alternatives

This HOWTO is meant to be a repository of alternative Gentoo installation methods, for those with special installation needs such as lack of a cdrom or a computer that can't boot CDs.

About this document
If the standard boot-from-CD install method doesn't work for you (or you just don't like it), help is now here. This document serves to provide a repository of alternative Gentoo Linux installation techniques to those who need them. Or, if you prefer, it serves as a place to put your wacky installation methods. If you have an installation method that you yourself find useful, or you have devised an amusing way of installing Gentoo, please don't hesitate to write something up and post it on Bugzilla.

Booting the Install CD with Smart BootManager
Download Smart BootManager available from http://btmgr.sourceforge.net/download.html. Linux source or binary format and windows .exe versions are available as well as many language packs. However, at this time, the preferred method would be to use the binary format, as the source will not compile with newer versions of NASM.

Either compile the package from source or just grab the binary. There are several options that can be utilized while creating your boot floppy, as seen below.

Use  to build the boot floppy:

Now simply place the floppy in the floppy drive of the computer you'd like to boot the Install CD on, as well as placing the Install CD in the CD-ROM and boot the computer.

You'll be greeted with the Smart BootManager dialog. Select your CD-ROM and press ENTER to boot the Install CD. Once booted proceed with the standard installation instructions.

Further information on Smart BootManager may be found at http://btmgr.sourceforge.net/.

Introduction
It is possible to boot some other LiveCD besides the Gentoo-provided CDs. This will give you a functional environment to use while you're compiling and installing Gentoo. The instructions provided here should work in principle with just about any other LiveCD.

There are too many LiveCDs out there to list, but you might try Knoppix. It provides a full graphical desktop, with office applications, web browsers, and games to keep you busy. Knoppix is only available for x86 users, so depending on your needs you may need to find a different LiveCD.

Installation instructions
Boot from your LiveCD. Open a terminal and run su - so you can change your password. This lets you set the root password for the CD. You can now configure the sshd daemon for remote login if you need to install Gentoo remotely. Next, you'll need to create the mount point.

At this point, you can pick up with the standard install documentation at Preparing the Disks. However, when you are asked to mount the proc system, issue the following command instead:

When you're ready to unpack the stage tarball in Unpacking the stage tarball, you will need to use a different tar command to ensure that proper group IDs are enforced on the unpacked stage:

If you are using Ubuntu, note that is a symbolic link to. You must bind or create a tmpfs at this location (within the chroot path). On the system before chroot'ing:

This is to avoid where Python sees   as broken (due to lack of ) and Portage seeing that as an error (technically Python configuration would continue and build assuming   but this would lead to a very undesired Python build).

Once you're ready to chroot into your unpacked stage in Installing Base System, you will need to use a different chroot command sequence. This ensures that your environment variables are properly setup.

Finally, know that some Portage FEATURES may not work in your LiveCD. Especially watch out for  and. If you find yourself getting errors, it might be wise to disable some or all of the optional FEATURES.

Diskless install using PXE and kernel/initrd/squashfs from the LiveCD
This method is easier to configure than PXE boot based on iSCSI or NFS. Multiple machines can boot from the same set of images distributed via TFTP and can be easily extended to also work over HTTP or other protocol.

Some other distributions including Fedora already distribute images needed to bootstrap a live or installation CD but with Gentoo it's necessary to (1) extract kernel, initrd and squashfs from the live CD, (2) patch initrd contents and (3) merge squashfs into initrd. Only then it is possible to configure a PXE based boot loader that will load the images and boot into a live system.

Save the following script and make sure it is executable and in  or follow its steps manually.

Download  (or try with the current version if it differs). Install, make sure it serves  and start it.

Run the script with the appropriate parameters.

Now your tftp boot service is ready and you need to configure your DHCP service. You can set up DHCP server on the same machine and make sure booted machines are connected to it, or you can just tweak the configuration of your existing router.

Example configuration for OpenWRT dhcp service follows:

Requirements
PXE (Preboot eXecution Environment) is a method for booting computers over a PXE-capable network interface (and using a PXE-supporting BIOS). It is also supported as a boot method from block devices (like CDs or USBs) in case the system does not support PXE boot from the network interface or BIOS. In such cases, a minimal boot environment mimics the PXE supporting network card (see also Etherboot/gPXE).

Server base setup
Create directories: The first thing to do is to create the directories where your diskless system will be stored. Create a directory called which houses a directory for each diskless client. For the rest of this howto we'll be working on the client 'eta'.

DHCP and TFTP setup: The client will get boot informations using DHCP and download all the required files using TFTP.

For dhcpd, just run  (or any other DHCP server of your choice). Make sure that the correct interface is selected in, and configure it for your basic needs. Then, add the following on.

Next you'll need to configure your interface in so that it doesn't get cleared at bootup. See for more information.

For TFTP, emerge. In, put the following:

Setup GRUB: Older versions of GRUB used the  USE flag to create a PXE image.

Install GRUB.

Once GRUB is compiled, create the diskless client's boot directory.

Original way was to copy the PXE image to the diskless client but the path doesn't seem to exit any more.

Then edit its config file.

Setup NFS: NFS is quite easy to configure. The only thing you have to do is to add a line on the config file:

Update your hosts: One important thing to do now is to modify your file to fit your needs.

Creating the system on the server
You might want to reboot the server with a Gentoo Install CD, although you can very well continue immediately if you know how to proceed with the Gentoo Installation Instructions from an existing installation. Follow the standard install procedure as explained in the Gentoo Handbook BUT with the following differences: When you mount the file system, do the following (where is the partition where you created the  directory). You do not need to mount any other partitions as all of the files will reside in the directory.

Stage tarballs and chroot: This example uses a stage3 tarball. Mount to your diskless directory and chroot into it to continue with the install. Then follow the installation manual until kernel configuration.

Kernel configuration: When you do the  of your kernel configuration, don't forget to enable the following options with the others recommended into the install howto.

Save the kernel in your chrooted (not in ) according to the pxegrub setting defined earlier. Next configure your diskless client's.

You also need to prevent the client to run a filesystem check:

Install since your client will heavily depend on it:

Bootloader. Don't install another bootloader because we already have one - pxegrub. Simply finish the install and restart the server. Start the services you'll need to boot the new client: DHCP, TFTPD, and NFS.

Booting the new client
For the new client to boot properly, you'll need to configure the BIOS and the network card to use PXE as the first boot method - before CD-ROM or floppy. For help with this consult your hardware manuals or manufacturers website. The network card should get an IP address using DHCP and download the GRUB PXE image using TFTP. Then, you should see a nice black and white GRUB bootmenu where you will select the kernel to boot and press Enter. If everything is ok the kernel should boot, mount the root filesystem using NFS and provide you with a login prompt. Enjoy.

Requirements
In order to install Gentoo from your existing Linux distribution you need to have chroot command installed, and have a copy of the Gentoo installation tarball or ISO you want to install. A network connection would be preferable if you want more than what's supplied in your tarball. (by the way, a tarball is just a file ending in .tbz or .tar.gz). Let's get started!

Overview
We will first allocate a partition to Gentoo by resizing our existing Linux partition, mount the partition, untar the tarball to the partition that is mounted, chroot inside the pseudo-system and start building. Once the bootstrap process is done, we will do some final configuration on the system so as to make sure it boots, then we are ready to reboot and use Gentoo.

How should we make space for Gentoo?
The root partition is the filesystem mounted under. A quick run of  on my system shows what I am talking about. We well also use  (disk free) to see how much space I have left and how I will be resizing. Note that it is not mandatory to resize your root partition! You could be resizing anything else supported by our resizer, but let's talk about that later.

As we can see, the partition mounted as named  has 2.4 GB free. In my case, I think I will resize it as to leave 400 MB free of space, therefore allocating 2 GB for Gentoo. Not bad, I could have quite some stuff installed. However, I think that even 1 GB is enough for most users. So let's partition this thing!

Building parted to resize partition
is an utility supplied by the GNU foundation, an old and respectable huge project whose software you are using in this very moment. There is one tool, however, that is extremely useful for us at the moment. It's called, partition editor and we can get it from http://www.gnu.org/software/parted/.

Look up on that page the type of file system you want to resize and see if parted can do it. If not, you're out of luck, you will have to destroy some partition to make space for Gentoo, and reinstall back. Go ahead by downloading the software, install it. Here we have a problem. We want to resize our Linux root partition, therefore we must boot from a floppy disk a minimal Linux system and use previously-compiled parted copied to a diskette in order to resize. However, if you can unmount the partition while still in Linux you are lucky, you don't need to do what follows. Just compile parted and run it on an unmounted partition you chose to resize. Here's how I did it for my system.

Get the mininux boot/root disk (a 2.4-powered mini Linux distribution on a floppy - free of charge) from http://mininux.free.fr/uk/, create a floppy as suggested in the Documentation that accompanies the software package and insert a new floppy in the drive for the next step.

We will now proceed with the build of parted. If it's not already downloaded and untarred, do so now and  into the corresponding directory. Now run the following set of commands to build the utility and copy it to your floppy disk.

Congratulations, you are ready to reboot and resize your partition. Do this only after taking a quick look at the parted documentation on the GNU website. The resize should take under 30 minutes for the largest hard-drives, be patient. Reboot your system with the mininux boot disk (just pop it inside), and once you are logged in, switch the disk in the drive with your utility disk we have created above and type  to have parted under. There you go. Run parted and you will be able to resize your partition. Once this lenghty process done, we are ready to have the real fun, by installing Gentoo. Reboot back into your old Linux system for now. The drive you wish to operate on is the drive containing the partition we want to resize. For example, if we want to resize, the drive is.

Once you have resized, boot back into your old Linux as described. Then go to The Gentoo Handbook: Preparing the Disks and follow the instructions. When chrooting, use the following command to flush your environment:

Enjoy!