[linux-lvm] vgcreate failed when using iscsi + dm-multipath + lvm

[David Teigland]

On Mon, Mar 13, 2017 at 06:12:06PM -0700, Neutron Sharc wrote:
> error 1:
>  Physical volume '/dev/mapper/360000000557b690283509c3709c4fc0b' is
> already in volume group 'vol8',
>  Unable to add physical volume
> '/dev/mapper/360000000557b690283509c3709c4fc0b' to volume group
> 'vol14'.
> 
> error 2:
>  Found duplicate PV W9rMQ0GuoNw9rnzK8x47OVEY044A2mgT: using
> /dev/mapper/360000000a1d91e849f66dd53a61d8fa9
>  not /dev/mapper/360000000e2ddd2a9380e9159902d9f73,  Using duplicate
> PV /dev/mapper/360000000a1d91e849f66dd53a61d8fa9 without holders,
> replacing /dev/mapper/360000000e2ddd2a9380e9159902d9f73,
> 
> error 3:
> Can't open /dev/mapper/360000000e2ddd2a9380e9159902d9f73 exclusively.
> Mounted filesystem?
> Unable to add physical volume
> '/dev/mapper/360000000e2ddd2a9380e9159902d9f73' to volume group
> 'vol2'.

Fairly common problem, lvm needs to see only the multipath device and not
the components.  Make sure lvm.conf has multipath_component_detection
enabled.  There was also a recent related fix:
  lvmetad: use udev to ignore multipath components during scan