Once you have written an operating system declaration, as seen in the
previous section, it can be instantiated using the
system command. The synopsis is:
guix system options… action file
file must be the name of a file containing an
operating-system declaration. action specifies how the
operating system is instantiate. Currently the following values are
Build the operating system described in file, activate it, and switch to it18.
This effects all the configuration specified in file: user accounts, system services, global package list, setuid programs, etc.
It also adds a GRUB menu entry for the new OS configuration, and moves entries for older configurations to a submenu—unless --no-grub is passed.
It is highly recommended to run
guix pull once before you run
guix system reconfigure for the first time (see Invoking guix pull). Failing to do that you would see an older version of Guix
reconfigure has completed.
Build the operating system’s derivation, which includes all the configuration files and programs needed to boot and run the system. This action does not actually install anything.
Populate the given directory with all the files necessary to run the operating system specified in file. This is useful for first-time installations of GuixSD. For instance:
guix system init my-os-config.scm /mnt
copies to /mnt all the store items required by the configuration specified in my-os-config.scm. This includes configuration files, packages, and so on. It also creates other essential files needed for the system to operate correctly—e.g., the /etc, /var, and /run directories, and the /bin/sh file.
This command also installs GRUB on the device specified in my-os-config, unless the --no-grub option was passed.
Build a virtual machine that contain the operating system declared in file, and return a script to run that virtual machine (VM). Arguments given to the script are passed as is to QEMU.
The VM shares its store with the host system.
Additional file systems can be shared between the host and the VM using
--expose command-line options: the former
specifies a directory to be shared with write access, while the latter
provides read-only access to the shared directory.
The example below creates a VM in which the user’s home directory is accessible read-only, and where the /exchange directory is a read-write mapping of the host’s $HOME/tmp:
guix system vm my-config.scm \ --expose=$HOME --share=$HOME/tmp=/exchange
On GNU/Linux, the default is to boot directly to the kernel; this has the advantage of requiring only a very tiny root disk image since the host’s store can then be mounted.
--full-boot option forces a complete boot sequence, starting
with the bootloader. This requires more disk space since a root image
containing at least the kernel, initrd, and bootloader data files must
be created. The
--image-size option can be used to specify the
Return a virtual machine or disk image of the operating system declared in file that stands alone. Use the --image-size option to specify the size of the image.
vm-image, the returned image is in qcow2 format, which
the QEMU emulator can efficiently use.
disk-image, a raw disk image is produced; it can be
copied as is to a USB stick, for instance. Assuming
the device corresponding to a USB stick, one can copy the image on it
using the following command:
# dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
options can contain any of the common build options provided by
guix build (see Invoking guix build). In addition,
options can contain one of the following:
Attempt to build for system instead of the host’s system type.
This works as per
guix build (see Invoking guix build).
disk-image actions, create an image
of the given size. size may be a number of bytes, or it may
include a unit as a suffix (see size specifications in GNU Coreutils).
Apply strategy when an error occurs when reading file. strategy may be one of the following:
Report the error concisely and exit. This is the default strategy.
Likewise, but also display a backtrace.
Report the error and enter Guile’s debugger. From there, you can run
commands such as
,bt to get a backtrace,
display local variable values, and more generally inspect the program’s
state. See Debug Commands in GNU Guile Reference Manual, for
a list of available debugging commands.
Note that all the actions above, except
rely on KVM support in the Linux-Libre kernel. Specifically, the
machine should have hardware virtualization support, the corresponding
KVM kernel module should be loaded, and the /dev/kvm device node
must exist and be readable and writable by the user and by the daemon’s
This action is usable only on systems already running GNU.