Adventures so far...
I've pasted a working system configuration at the bottom.
The idea is to boot / as tmpfs, and to mount the minimal set of
directories from persistent storage:
* /boot
* /gnu
* /home is not strictly required, but is useful!
* /var/guix
What's working:
* Booting to GNOME
* `guix system reconfigure`
* Booting previous generations
* /etc and /var are empty upon boot, woo!
A few issues:
* Bootstrapping all this is non-trivial. It requires fiddling with
partitions, and getting it wrong can easily make your system unbootable.
Suggestions? Maybe the user could set up bind-mounts to map to their
preferred partition scheme? A basic cookbook entry could bind-mount
directories from a single ext4 partition to the required directories.
* I tried setting up /gnu and /var/guix as bind-mounts per
but this didn't seem to work from initrd: the kernel panic'd on boot. I
need to confirm this and raise a bug.
* Mounting / as tmpfs falsely requires a device, otherwise it waits
forever on boot. I need to confirm this and raise a bug.
* Activation-on-boot fails due to inexistence of /run and /var/run.
Here's the config:
(use-modules (gnu))
(use-service-modules desktop networking ssh xorg)
(operating-system
(timezone "Australia/Sydney")
(host-name "test")
(users (cons* (user-account
(name "tom")
(comment "Tom")
(group "users")
(home-directory "/home/tom")
;; Needed since /etc/passwd is not persisted.
(password (crypt "password" "foobar"))
(supplementary-groups
'("wheel" "netdev" "audio" "video")))
%base-user-accounts))
(packages
(append
(list
(specification->package "emacs-next"))
%base-packages))
(services
(append
(list (service gnome-desktop-service-type)
(set-xorg-configuration
(xorg-configuration
(keyboard-layout keyboard-layout))))
%desktop-services))
(bootloader
(bootloader-configuration
(bootloader grub-bootloader)
(target "/dev/sda")
(keyboard-layout keyboard-layout)))
(file-systems
(cons* (file-system
(mount-point "/")
(device
;; TODO: Raise bug that root-as-tmpfs falsely requires a partition.
(uuid "59457d60-2b08-4f5c-b1c7-e29cd5f7a3da"
'btrfs))
(options "size=1G")
(type "tmpfs"))
(file-system
(mount-point "/boot")
(device
(uuid "59457d60-2b08-4f5c-b1c7-e29cd5f7a3da"
'btrfs))
(options "subvol=boot")
(needed-for-boot? #t)
(type "btrfs"))
(file-system
(mount-point "/home")
(device
(uuid "59457d60-2b08-4f5c-b1c7-e29cd5f7a3da"
'btrfs))
(options "subvol=home")
(type "btrfs"))
(file-system
(mount-point "/var/guix")
(device
(uuid "59457d60-2b08-4f5c-b1c7-e29cd5f7a3da"
'btrfs))
(options "subvol=var/guix")
;; Needed to boot old generations, which needs /var/guix/profiles/
(needed-for-boot? #t)
(type "btrfs"))
(file-system
(mount-point "/gnu")
(device
(uuid "59457d60-2b08-4f5c-b1c7-e29cd5f7a3da"
'btrfs))
(options "subvol=gnu")
(needed-for-boot? #t)
(type "btrfs"))
%base-file-systems)))
