Re: btrfs and subvolumes for root

[maze]

Am 2017-08-06 05:46, schrieb Fredrik Salomonsson:
> Hello Guix,
>
> I'm testing out setting up a dual boot between GuixSD and Arch. I've
> no idea how much each one will take on disk. I decided to try out
> btrfs and subvolumes for the layout.
>
> But I'm having some issues booting the thing.
>
> My disk layout right now is:
> sda
>   sda1      1MB BIOS boot
>   sda2      4G  swap
>   sda3 228.9GB  btrfs
>
> then subvolumes:
> sda3/
>   __current/guixsd-root
>   __current/arch-root
>   __current/boot
>   __current/home
>
> section from my config.scm, which is based on my old config (old one
> is attached).
>
> (file-systems (cons* (file-system
>    (device "root")
>    (title 'label)
>    (mount-point "/boot")
>    (options
> "defaults,discard,compress=lzo,space_cache,autodefrag,subvol=__current/boot")
>    (dependecies mapped-devices))
> ;; repeat for guixsd-root and home but with correct value for subvol
> )
>
> guix system init worked fine but when booting it fails to locate the
> bzImage. Which I assume is because it doesn't know that the root is in
> a subvolume.
>
> Long story short. How do I add rootflags to GuixSD's grub menu entry?
> Need to add "rootflags=subvol=__current/guixsd-root" to the
> linux-arguments. Might be an issue of having boot as a subvolume as
> well.
>
> Thanks
>
> --
>
> s/Fred[re]+i[ck]+/Fredrik/g

Hello Fredrik,

I am having the same problem. Adjusting the kernel parameters for the 
GuixSD kernel seems currently not supported.  Looking at the source code 
though it looks like this could be achieved via manipulating the 
"bootloader-configuration-menu-entries" list. (Still a scheme noob!)

That said, it would generally make sense to make this configurable IMO.

Best
Martin