[linux-lvm] Discussion: performance issue on event activation mode

[Martin Wilck]

On Di, 2021-06-08 at 15:56 +0200, Peter Rajnoha wrote:
> 
> The issue is that we're relying now on udev db records that contain
> info about mpath and MD components - without this, the detection (and
> hence filtering) could fail in certain cases. So if go without
> checking
> udev db, that'll be a step back. As an alternative, we'd need to call
> out mpath and MD directly from LVM2 if we really wanted to avoid
> checking udev db (but then, we're checking the same thing that is
> already checked by udev means).

Recent multipath-tools ships the "libmpathvalid" library that
could be used for this purpose, to make the logic comply with what
multipathd itself uses. It could be used as an alternative to libudev
for this part of the equation.

Martin