If it is a kernel bug have you tried booting off an older kernel - you get a few seconds to select another kernel when grub loads.

Jun 13 03:56:10 Orion systemd: Device dev-disk-by\x2dpartlabel-primary.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:01.1/0000:02:00.0/ata17/host16/target16:0:0/16:0:0:0/block/sdk/sdk1 and /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/ata8/host7/target7:0:0/7:0:0:0/block/sdh/sdh1

Jun 13 03:56:10 Orion systemd: Device dev-disk-by\x2dpartlabel-primary.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:01.1/0000:02:00.0/ata17/host16/target16:0:0/16:0:0:0/block/sdk/sdk1 and /sys/devices/pci0000:00/0000:00:1f.2/ata4/host3/target3:0:0/3:0:0:0/block/sdd/sdd1

I'm getting hundreds of these too showing up in Reports - Log Viewer - Messages!
Is this a kernel bug? my uuid's are all unique.

You can use something like parted (e.g GParted live CD) to create a new UUID for a disk and probably there is something you can do directly in ClearOS. You'd probably have to unmount the disk first (I can't imagine you would not).

[edit]
Check out uuidgen and this article, for example.
[/edit]

I've never cloned the disks
I had 3 x 320Gb in RAID5 and decided to grow to 3 x 1Tb
The process was, fail one drive, remove it, replace it for the 1Tb drive, rebuild RAID. This was made for all 3 drives.
After this I grew the partitions to accommodate the free space.

I'll try to find something about the uuid's

Have you ever cloned a disk? I'm guessing that the uuid is the same on /sdc and /sdd .

I don't know if this will work! But I would back up my data, fail ONE drive from the array, erase all partitions from said drive, repartition, add the drive back and wait for the array to rebuild' then repeat on the other drive.

Eric Anderson wrote:

what does this say?

#mdadm --detail /dev/md127

#lsblk -o NAME,PARTLABEL

The mdadm says it's clean, I'm receiving daily email, all of them reporting that the RAID is Clean

mdadm --detail /dev/md127 

/dev/md127:

        Version : 1.2

  Creation Time : Tue Oct 20 00:38:33 2015

     Raid Level : raid5

     Array Size : 1953259520 (1862.77 GiB 2000.14 GB)

  Used Dev Size : 976629760 (931.39 GiB 1000.07 GB)

   Raid Devices : 3

  Total Devices : 3

    Persistence : Superblock is persistent



  Intent Bitmap : Internal



    Update Time : Wed Jun  8 09:20:25 2016

          State : active 

 Active Devices : 3

Working Devices : 3

 Failed Devices : 0

  Spare Devices : 0



         Layout : left-symmetric

     Chunk Size : 512K



           Name : SERVER.lanv00

           UUID : 926eda6c:8285bb30:1fdf3327:8f00e5a8

         Events : 16612855



    Number   Major   Minor   RaidDevice State

       5       8       17        0      active sync   /dev/sdb1

       4       8       33        1      active sync   /dev/sdc1

       3       8       49        2      active sync   /dev/sdd1

lsblk -i -o NAME,PARTLABEL

NAME                      PARTLABEL

sda                       

|-sda1                    

`-sda2                    

sdb                       

`-sdb1                    primary

  `-md127                 

    |-clearos_server-usr  

    |-clearos_server-home 

    `-clearos_server-var  

sdc                       

`-sdc1                    primary

  `-md127                 

    |-clearos_server-usr  

    |-clearos_server-home 

    `-clearos_server-var  

sdd                       

`-sdd1                    primary

  `-md127                 

    |-clearos_server-usr  

    |-clearos_server-home 

    `-clearos_server-var  

This message is appearing more often than I realized.
Some times keeps popping for long periods of time, and nor always showing "md127: unknown partition table"

.

what does this say?

#mdadm --detail /dev/md127

#lsblk -o NAME,PARTLABEL