Installing additional software packages with pacman

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To keep it lightweight and fast, SystemRescue just comes with software that is
directly related to the goals of diagnosing and fixing system problems. But
additional programs can easily be installed from the repositories provided by
Arch Linux.

pacman Basics

pacman is the program used for installing and managing packages. Before using
it, you have to download a copy of the package repository database, so that
pacman knows which packages are available and how they relate to each other.

This can be done like this (requires Internet access): pacman -Sy

Afterwards you can download and install new packages like this:
pacman -S <package name>

Keep in mind that it may require a lot of space in the writable layer (stored in
memory by default) to download and install additional packages. So it can fail
if too many packages are requested.

Searching

When you don’t know the exact name of a package you want to install, you can
search for text parts in the package name and description:
pacman -Ss <search string>

Once you know the package name, you can get more information about a not yet
installed package like this: pacman -Si <package name>

You can also search for packages that provide a given filename. You have to
download the separate files database first: pacman -Fy Afterwards you can
search for packages by filename: pacman -F <filename>

Snapshot vs. Rolling

SystemRescue from Version 8.07 onwards by default accesses the repositories in a
state frozen at the moment of the SystemRescue release. This is done to prevent
huge downloads due to dependencies and conflicts. This is called the snapshot
configuration of pacman. It is implemented by using the
Arch Linux Archive
from the release date.

Arch Linux in contrast has a rolling release scheme where even older
installations always get the newest packages. This can also be accessed from
SystemRescue by activating the rolling configuration of pacman.

Changing to Rolling configuration

Both configuration variants of pacman are installed in parallel. You can change
to the rolling variant on a per-command basis with the --config parameter:
pacman --config=/etc/pacman-rolling.conf <pacman command>

Both configurations have separate remote repository databases. So you have to
download them for the rolling config before you can use it:
pacman --config=/etc/pacman-rolling.conf -Sy

You can also permanently change to the rolling configuration by pointing the
symlink /etc/pacman.conf to /etc/pacman-rolling.conf.

Be extra careful when using the rolling configuration though. You can accidently
render your system unstable for example by updating the Linux kernel package.
Then the modules won’t match the running kernel anymore. Updates like this don’t
necessarily need to be done on purpose, but could come through a dependency from
installing or updating another package.

Repositories

Arch Linux provides several different repositories. SystemRescue only has the
official repositories core, extra and community preconfigured.

You can configure more
Official and
Unofficial
repositories. But be aware that other repositories often will conflict with the
default snapshot configuration.

You can search for packages here: archlinux.org/packages/

More information

You can find more information about pacman and it’s usage at
wiki.archlinux.org/title/pacman