On Tue, 2023-11-14 at 15:02 -0600, David Teigland wrote:
>
> 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.
How would that addition of the multipath device come to pass?
By someone explicitly calling "lvmdevices" on it?
1 - someone creates a PV on a normal single-path SCSI device
2 - on subsequent boot, a new path has been added (e.g. by a Fibre
Channel zoning change)
3 - what happens before the user makes any change to system.devices?
a) LVM attempts to add one of the SCSI (path) devices as PV
(which might be grabbed by multipathd already)
b) LVM attempts to add the multipath device automatically,
somehow figuring out what happened
c) neither is attempted, and the PV is missing
Thanks,
Martin
