Re: LVM in LVM

[Steve Keller <keller.steve@gmx.de>]

Tim Woodall <debianuser@woodall.me.uk> writes:

> On Mon, 16 Sep 2024, Steve Keller wrote:
>
> > I don't see how this can be done in the current Debian 12.

> Not sure because I've previously battled the opposite problem but I'd
> start here in lvm.conf
>
>          # Configuration option devices/scan_lvs.
>          # Scan LVM LVs for layered PVs, allowing LVs to be used as PVs.
>          # When 1, LVM will detect PVs layered on LVs, and caution must
>          # be
>          # taken to avoid a host accessing a layered VG that may not
>          # belong
>          # to it, e.g. from a guest image. This generally requires
>          # excluding
>          # the LVs with device filters. Also, when this setting is
>          # enabled,
>          # every LVM command will scan every active LV on the system
>          # (unless
>          # filtered), which can cause performance problems on systems
>          # with
>          # many active LVs. When this setting is 0, LVM will not detect
>          # or
>          # use PVs that exist on LVs, and will not allow a PV to be
>          # created on
>          # an LV. The LVs are ignored using a built in device filter that
>          # identifies and excludes LVs.
>          scan_lvs = 0

Thanks, that's exactly what I was looking for.  I've set scan_lvs = 1
and called vgscan, and now I see the embedded PV and can activate it.
In older Debian releases this was default and changed sometime after
Debian 9.

Steve