# Configuration option devices/scan_lvs.
# Allow LVM LVs to be used as PVs. When enabled, LVM commands
will
# scan active LVs to look for other PVs. Caution is required to
# avoid using PVs that belong to guest images stored on LVs.
# When enabled, the LVs scanned should be restricted using the
# devices file or the filter. This option does not enable
autoactivation
# of layered VGs, which requires editing LVM udev rules (see
LVM_PVSCAN_ON_LVS.)
# This configuration option has an automatic default value.
# scan_lvs = 1
I had no luck on googling LVM_PVSCAN_ON_LVS
> I disabled it on my systems(and the 1000's of enterprise machines I
> used to support) because it caused random PV's to not be found
> sometimes.  Typically if something causes a pv to not get found it
> will be repeatable on that given system(likely some timing problem).
>
> The only useful thing it does is it speeds up scans when a disk is
> spun down and/or when you have 1000's of disks. But it does not
> speed
> anything up that much unless you have a huge number of disks that are
> spun down. On large san systems the testing I did said without it it
> would take 2-3 seconds to scan 1000's of disks (worth the wait given
> the random failures that caused havoc), verses immediate.
>
> And tiny changes in lvm/udev rules have changed it from working to
> broken.
>
> On Sun, Feb 16, 2025 at 9:11â?¯AM <christophe.ochal@xxxxxxxxx> wrote:
> >
> > I'm at present fighting with LVM2, for some weird reason I can't
> > get my
> > lvm volume
> > to be activated & mounted at boot resulting in me having to do
> > "vgchange -ay" at boot (after I'm dropped in a shell & prompted for
> > my
> > root password,to make debugging even more troublesome I can only
> > mess
> > with this over the weekends, i've included the lvmdump to this
> > mail,
> > any more help would be very welcome, as i'm at a loss of how to
> > proceed. this might also have relevant information.
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=2338735
> >
> >
> >
> >
