Re: [RFC next 0/2] dm: lvm: Initial Logical Volume Management support

["Sascha Hauer" <s.hauer@pengutronix.de>]

Hi Tobias,

On 2026-08-24 18:31, Tobias Waldekranz wrote:
> This is an initial RFC on the addition of LVM support to Barebox.
> 
> Avid readers of Barebox lore might remember me describing LVM support
> as a key part of my roadmap of how I would like to boot future
> versions of Infix - a network centric OS I work on - in the original
> device mapper series. [1]
> 
> I have finally gotten some time to get this in a presentable state.
> 
> Example session:
> 
>     wkz@spa:~/src/github.com/barebox/barebox$ ./barebox -i disk0=infix-x86_64.disk,blkdev
>     [...]
>     barebox@Sandbox:/ lvm info
>     VG "internal":
>       UUID:    sN8htx-oD18-wHWH-SuCU-1EWy-th1l-5WPU6j
>       SeqNum:  1
>       Size:    132 MiB (1 MiB extents)
>       #PV:     1
>       #LV:     1
>       PV disk0.2:
>         UUID:  6VHjVF-WVt7-Gk4Y-oTrK-lsgY-ve7N-GJ0CUn
>         Size:  134 MiB
>       LV "infix-x86_64.raw":
>         UUID:  Xp76Ig-9XXj-aBfK-Xv2U-rbsY-nEWX-omt4Bo
>         Type:  linear
>         Size:  132 MiB
>     barebox@Sandbox:/ lvm activate internal infix-x86_64.raw
>     [GPT warnings...]
>     Created internal-infix-x86_64.raw
>     barebox@Sandbox:/ ls /mnt/internal-infix-x86_64.raw.0/
>     mounted /dev/internal-infix-x86_64.raw.0 on /mnt/internal-infix-x86_64.raw.0
>     bin       boot      cfg       config    dev       etc       home
>     lib       lib64     loader    log       media     mnt       opt
>     proc      root      run       sbin      srv       sys       tmp
>     usr       var
>     barebox@Sandbox:/
> 
> If the overall structure is OK with the community and maintainers,
> then the biggest remaining issue is testing. I have been surprised to
> learn that the standard LVM tools will not operate on disk images
> (without loopback mounting). Nor does there seem to be any other tools
> out there that allows you to provision PVs/VGs/LVs without having them
> "live" and attached to the host system. If there are any suggestions
> here they would be very welcome!

Would guestfish be an option? That allows you to call pvcreate/vgcreate
on disk images.

Sascha