Comment 8 for bug 1619844

I think i have a specification to this issue.

First, my system with the same problem at shutdown/reboot, but only in a very special case:

Fresh install of Ubuntu Server 16.04.2 LTS
CPU: Intel Xeon E3-1245v6 (Kabylake)
Mainboard: MSI C236A Workstation/Server Mainboard (model: 7998-012R; latest BIOS: v2.7)
RAM: 4x TRANSCEND 8GB DDR4 2133 ECC-DIMM 2Rx8 1Gx72 288P 512Mx8/CL15 (model: TS1GLH72V1H)
SSD: 2x Samsung Basic MZ-7KE256BW 850 Pro interne SSD 256GB
HDD: 2x Western Digital Red 4TB NAS (model: WDBMMA0040HNC-ERSN)

Description of the special case with the shutdown/reboot issue:

The problem only reveals when RAID-Mode auf the MSI Mainboard is enabled. After resetting to AHCI-Mode, the problem is over an the server works fine. It seems, that's a problem with the "Intel® C236 Chipset" or more specific a driver problem with intel based components on the different systems.