Re: Guix/GNU/Linux multi distro + GuixSD multi-site scenario

[Alex Kost <alezost@gmail.com>]

myglc2 (2016-03-27 20:18 +0300) wrote:

> Christopher Allan Webber <cwebber@dustycloud.org> writes:
>
>> myglc2 writes:
>>
>>> Christopher Allan Webber <cwebber@dustycloud.org> writes:
>>> [...]
>>>>
>>>> Running all machines, I dunno.  I do dual-boot Debian and GuixSD with
>>>> them sharing the same user profile and store.
>>>
>>> Dual boot. Now that is cool!
>>
>> Dual booting allowed me to switch to GuixSD a lot more feasibly than I
>> could have otherwise.  I installed it on this laptop right before a 3
>> month trip.  Dual booting meant that when something wasn't in GuixSD
>> yet, no problem, I could switch to Debian for a bit.  Then I could work
>> on packages at my leisure to switch over.
>>
>> The trick was realizing that the grub that Guix generates wasn't the one
>> I should boot into... I needed to have Guix and Debian generate their
>> own grub files on their own partitions, and then have a /boot/ grub
>> which was reeeeaally small and simply had menu options to import those
>> other grub files.
>
> Neat!. Normally grub would be installed like this...
>
>   (bootloader (grub-configuration (device "/dev/sda")))
>   (file-systems (cons (file-system
>                         (device "/dev/sda1")
>                         (title 'device)
>                         (mount-point "/")
>                         (type "ext4"))
>                       %base-file-systems))
>
> But it sounds like you are installing a custom /boot/grub in
> /dev/sda. So where is the GuixSD Grub and /?

Hi, I also use double boot (GuixSD and ArchLinux).  I do it like this:
at first I never let GuixSD to reinstall grub by using --no-grub option
("guix system reconfigure --no-grub ...").  Instead I installed grub
manually (into a separate "boot" partition) and I use my own "grub.cfg",
which has an entry for the latest GuixSD system.  This entry may look
like this:

menuentry 'GuixSD' {
    search --no-floppy --label --set guix
    linux  /var/guix/profiles/system/kernel/bzImage --root=guix --system=/var/guix/profiles/system --load=/var/guix/profiles/system/boot
    initrd /var/guix/profiles/system/initrd
}

My grub config¹ also has entries for a previous system generation (I can
boot any generation by editing a number in a grub boot menu) and for a
particular system (sometimes I do "guix system build …" and put the
result directory of this "testing" system to my grub.cfg).

¹ https://github.com/alezost/config/blob/master/etc/grub.cfg

-- 
Alex