Enter the new system
Everything from here on happens inside the system you just installed:
arch-chroot /mnt
The prompt changes, and from that moment / means the new system,
pacman installs into it, and configuration files you edit are its
files rather than the installer’s.
What arch-chroot does
A bare chroot would give you the new filesystem and nothing else,
and most package scripts would fail. arch-chroot is a wrapper that
also bind-mounts /proc, /sys, /dev and /run from the live
system into the target, and copies /etc/resolv.conf across so that
name resolution works inside.
The practical result is that the chroot behaves like a running system for the purposes of installing packages and writing config.
What it is not
It is not booted. The new system’s systemd is not running –
the systemd you can see belongs to the live environment. That
distinction has one consequence you will meet immediately:
| Command | Inside the chroot |
|---|---|
systemctl enable foo |
Works. It only creates symlinks on disk |
systemctl start foo |
Does not work. There is no running init to ask |
systemctl status foo |
Reports on the live system, not the target |
So you enable services now and they start on the first real boot. Nothing you enable in this chapter runs until the machine reboots.
Getting back out
exit
Ctrl-D does the same thing. You can re-enter with arch-chroot /mnt as often as you like – it is not a one-shot operation, and
nothing is lost by leaving and coming back.
Confirm where you are
It is worth being certain which system you are typing into, because every remaining chapter depends on getting that right:
cat /etc/os-release | head -2 pacman -Q | wc -l
NAME="Arch Linux ARM" PRETTY_NAME="Arch Linux ARM" 166
On an x86_64 machine the name is Arch Linux. Either way the
package count is the interesting part: a fresh install of the set
above is a couple of hundred packages.
The live system has a far longer package list than a fresh install, so that count alone tells you which side of the chroot you are on.