CentOS - May 2016 - CENTOS 7.2.1511 Multipath and boot from SAN issue

Hi all,
I'm running a Centos 7.2.1511 freshly installed on a SAN device. Everything
is fine on the SAN side, but I have an issue with multipath or udev or systemd,
I'm not sure.
I when I boot my machine with the multipathd service enabled at boot, boot fails
beacause some partitions on the multipathed device are missing from /dev.
>From the boot rescue shell, if I do a fdisk -l /dev/mapper/mpatha, I see 8
partitions, if I do a ls -l /dev/disk/by-uuid/ I see only 6 devices, so two
devices are missing.
I have to run kpartx -a /dev/mapper/mpatha manually in order to reread the
partition table and recreate the 2 missing device. Only after that I'm able
to boot correctly.

Any idea of te root cause of this issue ?

device-mapper-multipath is 0.4.9-85.el7_2.4.x86_64

Thanks for your time.