Re: access LVM logical volume as disk?

[Jeff Rizzo <riz%tastylime.net@localhost>]

On 11/4/25 15:30, Robert Elz wrote:

>      Date:        Tue, 4 Nov 2025 23:12:05 -0000 (UTC)
>      From:        mlelstv%serpens.de@localhost (Michael van Elst)
>      Message-ID:  <10ee185$ajm$1%serpens.de@localhost>
>
>    | You can create a ccd device on top of a LV.
>
> What's the benefit of doing that (assuming just one member of the ccd) ?
>
> If the object /dev/mapper/vg0-lvpbulk works for gpt, and ccd, then isn't
> that already a device, at least for most practical purposes ?
>
> Wouldn't (if needed, that is, if it doesn't happen already)
>
> 	dkctl /dev/mapper/vg0-lvpbulk makewedges
>
> work to access the partitions inside a LV containing GPT partitioning?
>
> Note, I know nothing at all about LVM, treat all of this as questions
> from a curious bystander.


Unfortunately, no - the lvm devices (similar to zvols in the ZFS world)
don't support the necessary ioctls:


# dkctl /dev/mapper/rvg0-ubnt makewedges
dkctl: /dev/mapper/rvg0-ubnt: makewedges: Inappropriate ioctl for device


I agree that it would probably be more useful if they did, but here we are.

+j