[linux-lvm] system boot time regression when using lvm2-2.03.05

[David Teigland]

On Fri, Sep 06, 2019 at 08:51:47AM +0200, Martin Wilck wrote:
> IIUC this would mean that you skip David's "pvs_online" file generation
> entirely. How did the auto-activation happen, then?

I'd like to know which services/commands are activating the LVs.  In the
slow case it was clearly done by the lvm2-pvscan services, but in the fast
case it looked like it was not.

> Could it be that lvm2-activation-net.service activated the VGs?  I can
> imagine that that would be efficient, because when this service runs
> late in the boot process, I'd expect all PVs to be online, so
> everything can be activated in a single big swoop. Unfortunately, this
> wouldn't work in general, as it would be too late for booting from LVM
> volumes.
> 
> However I thought all lvm2-acticvation... services were gone with LVM
> 2.03?

They still exist.  In lvm 2.03, the lvm.conf event_activation setting
controls whether activation is event-based via lvm2-pvscan services, or
done by lvm2-activation services at fixed points during startup.  LVM
commands in initramfs could also be interfering and activating more than
the root LV.