Comment 9 for bug 1608495

Followed the instructions from comment #7:
Base installation: Xenial/16.04
ii mdadm 3.4-4ubuntu0.1
ii dracut-core 044+3-3

Using IMSM based mdadm mounted on /home:
/dev/mapper/datavg01-home 197G 121G 67G 65% /home

PV VG Fmt Attr PSize PFree
/dev/md126p6 datavg01 lvm2 a-- 831,50g 353,85g

dev/md126p6:
      Container : /dev/md/imsm0, member 0
     Raid Level : raid5
     Array Size : 871895713 (831.50 GiB 892.82 GB)
  Used Dev Size : unknown
   Raid Devices : 3
  Total Devices : 3

          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-asymmetric
     Chunk Size : 64K

           UUID : cc707f7d:77869bd6:de8d52a2:ca21e329
    Number Major Minor RaidDevice State
       2 8 16 0 active sync /dev/sdb
       1 8 32 1 active sync /dev/sdc
       0 8 48 2 active sync /dev/sdd

Now done 2 reboots, one from text console directly after installing the new packages and one from the GUI. In both cases the array came up in sync.