Re: discuss about commit 3b0f9ce: filter-mpath: get wwids from sysfs vpd_pg83

On Tue, Nov 14, 2023 at 05:58:52PM +0000, Martin Wilck wrote:
>     "mpath_uuid is used for dm multipath devices, reported by sysfs."
> 
> So users are supposed to use "mpath_uuid" if they want to use multipath
> devices as PVs? What if the user simply uses "sys_wwid" or "sys_serial"
> for a multipath device? Will LVM perform any kind of multipath
> detection, and if yes, how?

LVM will automatically, and only, allow mpath_uuid for multipath devices.

There is a special case that we look for in which a device is used by
itself originally, and included in system.devices with its wwid.  Later,
multipath is set up on that device.  When the multipath device is added to
system.devices, the component device is automatically removed.

Dave