Crear y usar una imagen viva de instalación

La herramienta oficial y soportada para crear un lápiz USB Fedora es la utilidad Fedora Media Writer, anteriormente conocida como LiveUSB Creator. Consulte la guía Fedora Media Writer en la descripción general de la Documentación de Usuario de Fedora.

Este método es para personas que ejecuten Linux u otro unix con GNOME, Nautilus y la Utilidad GNOME Disk instalados. Particularmente, si está usando una distribución distinta de Fedora que no soporte Flatpak, este puede ser el método más fácil disponible. Una instalación estándar de Fedora o una instalación estándar de GNOME de muchas otras distribuciones será capaz de usar este método. En Fedora, compruebe que están instalados los paquetes nautilus y gnome-disk-utility. Pueden estar disponibles para otros escritorios herramientas gráficas de escritura directa similares o puede usar el método de línea de comando direct write.

UNetbootin es un creador gráfico de imágenes USB de arranque. Usarlo le permitirá preservar cualquier dato que tenga en el dispositivo USB. Si tiene problemas al arrancar, sin embargo, es posible que desee probar con una unidad en blanco formateada limpiamente en FAT32.

Si ya está corriendo un CD, DVD o USB vivo y desea convertir esto en un lápiz USB de arranque, ejecute el siguiente comando:

La mayoría de los métodos de escritura requerirán que sepa el nombre de /dev de su lápiz USB, por ejemplo /dev/sdc, cuando los usa sobre Linux. Usted no necesita conocer esto para usar Fedora Media Writer. Para descubrir esto:

Puede probar su dispositivo usando QEMU.

Puede usar el script liveimage-mount del paquete livecd-tools para montar un dispositivo Live USB conectado u otra imagen LiveOS, como un ISO o Live CD. Esto es conveniente cuando desea copiar o eliminar algún archivo del sistema de archivos LiveOS en un Live USB, o simplemente examinar los archivos en un Live ISO o Live CD.

Para crear una imagen vive, se utilizan los paquetes livecd-creator y mock. Para esto, son necesarios privilegios de superusuario.

The livecd-creator tool is part of the _livecd-tools_package. If it is not installed on your system, add it and all other tools like mock, lorax, git, pykickstart and a text editor with DNF:

Hint: We are creating a livecd like the fedora-live-workstation image, which is totally localized, but has english as default. There is no need to install any localization support on your own. You can change it in the created kickstart.cfg if necessary.

We need to add you current user to the mock group, or you need to do anything as root user.

The $(whoami) adds your current user, as we do not know what username you are currently using ;)

A relogin to make the change effective, would be wise, or you switch to root now.

Let’s create the mock group:

If you now enter:

it shall output your username together with the old groups and the new group "mock". If this is not the case, you did something wrong.

Now we can init the build environment. In this example we use the most likely x86_64, but if you build it for ARM or PowerPC, you can just use a different config by changing the ARCH-Type to the desired plattform!

Mock creates us an empty toolbox for this, so we need to fill it with packages, which we will need to create the image later in the process. If you now think "Why so complicated?" you are only partly right, as a toolbox is a simple container, which we need to seperate the work for different releases of Fedora, otherwise you have to overwrite and mixing different builds on your own.

Make sure you have enogh free disk space for all these files and the ones, the livemedia-creator will download later. We suggest at least 10 GB free diskspace for this.

If you wanne use a different texteditor then "vim", you need to install it now, otherwise you are stuck to a not so well integrated basic "vim" installation, which will be a bit unpleasent to use. Don’t panic, we don’t do much editing inside the toolbox, vim will do :)

Now we enter the toolbox for the first time …​

This gives us a shell and networksupport, so the scripts inside the toolbox can access the internet and install packages from the repo.

You will see something like this output:

Now we need to download the kickstart files, which previouse Fedora releases had as a package, from the Fedora Servers:

You can access the page with a normal browser, to see which tags aka 'branches' like "f42" are available, in case you wanne do another version. What happens now is a git checkout into the current directory of your toolbox. Big advantage: no danger of overwriting files on your os.

ATTENTION: before you continue, make sure you have at least 10 GB of free storage on your systems partition as we will download a lot of rpms and create an image that is at least 2,3 GB in size. If you don’t have enough space, all future steps can faill with the wildest error messages and your will waste A LOT of time with it!

What we now need is a kickstart file. Never heared of it, don’t panic :D

A kickstart file contains informations about the size of the tmp drive in the later started live image, it mounts, its packages and so on. You will not need to reinvent the wheel, relax. Here is an example:

What you see is a subsection of all possible options, because that git checkout before, downloaded a full set of already working kickstart files, which we will join up to one new kickstart.cfg file.

The above file will remove packages and groups of packages from the later created image, compared to the normal Fedora-Live-Workstation image. We call this a DELTA-file, because we just define the differences between our image and the original Fedora Live Workstation image.

You see this:

This includes the original kickstart (ks) config for the original Fedora-Live-Workstation Image as a base file. The rest of the lines "overwrite" the sections in the original file. So you just tell kickstart what you want and not want compared to the Fedora-Live-Workstation image.

In this example, we removed some gnome-apps and end up what you know as "Fedora-Minimal-Workstation" Image.

Take that example and save it to a file you can name i.E. "example-START.ks". Make sure you can distingish your file later as the starting point of your work. Because now, we will "join" aka. "flatten" the included files to one big kickstart.cfg file, that we will need for livemedia-creator later.

The problem you are now facing is, it doesn’t work out-of-box, because ksflatten does not find all the includes it needs. You can solve this in two ways:

a) you move your ks file to the directory named "fedora-kickstarts" and switch to it with cd, or

b) you execute the above command and copy all files it names in the errormessage from "fedora-kickstarts" to "." untill it stops complaining.

From now on, you should only edit the created kickstart.cfg file for changes, otherwise you have to repeat the next step over and over again.

Either way, you end up with a defective cfg file, because the used include files define the mountpoint "/" two times, which lead to an error. That’s easily fixed:

search for "# Disk partitioning information" and change the two lines, that start with "part /" to this ONE line:

We will try to fix this, but it could take until Fedora 45.

Now the part you are waiting for: Let’s create the iso image.

Please replace the folling terms:

"MYPROJECTNAME" That is your internal project name, that ends up in /etc/os-release "MY_ID" that is the name of the mounted ISO file AND VERY IMPORTANT if you wanne refer to that iso in GRUB "<FILENAME>" thats the name of the created iso file unter /var/lmc

In approximitly 15 minutes, if everything works, you have a created <filename>.iso image IN YOUR TOOLBOX.

To get it out there, you enter …​

and copy it to the desired place. In example:

Now you can test your image in different ways:

a) you can use Gnome-Boxen to just run it in your desktop environment, which is way easier.

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b) use the QEMU line in the next section.

Congratulations: You are done creating our own live-image. Some tips on the way:

Como root:

Reemplace filename.iso con el nombre de la imagen Live CD creada y qemu-system-x86_64 con un binario qemu para el sistema objetivo, por ejemplo, qemu-system-i386.

La imagen viva puede incorporar funcionalidad para verificarse a si misma. Para hacerlo, necesita tener instalado isomd5sum tanto en el sistema usado para la creación de la imagen e instalada en la imagen. Esto es para que se puedan usar las utilidades implantisomd5 y checkisomd5. Estas utilidades aprovechan la posibilidad de incorporar un md5sum en el área de aplicación de la imagen iso9660. Esto se verifica antes de montar el sistema de archivos raíz real.