Re: access LVM logical volume as disk?

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Wed, 5 Nov 2025 06:07:39 -0000 (UTC)
    From:        mlelstv%serpens.de@localhost (Michael van Elst)
    Message-ID:  <10eepjb$dp5$1%serpens.de@localhost>

  | A wedge is similar to a device mapper logical volume, you cannot treat
  | it like a disk either.

Since a wedge is really simply a range of blocks from a disk-like device,
that's probably a mistake, but not an important one.   And were it to be
possible to partition (etc) wedges, doesn't mean that the kernel should
default to doing that.

  | The vnd driver should probably allow the same,

I actually disagree with that, vnd's job is to to provide a device interface
from a file (as in an object in some filesystem) as the storage.   It doesn't
really make a lot of sense to skip the file and turn a device into a device.
And I can certainly understand how the kernel might not like it if tried.

kre

ps: lvm could do with an lvm(4) overview page, which would describe what is
needed to include it in the kernel, plus give an overview of how the
pieces fit together.   Starting with lvm(8) isn't the ideal introduction.