Degraded Array - LVM drives causing a problem

Hi guys

I am pulling my hair out.

The situation is this, I have 3 x 2tb drives for Raid 5, then i used LVM to "merge" 2 x 1tb to make the 4th 2tb drive for the raid5.

It creates and everything is perfect, UNTIL i reboot. it then degrades and has lost the LVM merged drive in the array.
Under LVM in the webgui it all look fine, its all there???

I have deleted the VG and recreated it and recovered the array and rebuilt it (took forever). Then rebooted and the same thing happened again.

Please could someone help me out here, have lost 2 days of work trying to sort this sh*t out.

Thanks.....

Hi

Its OMV 0.5

Gigabyte FM1 Mainboard with 6 sata ports (all in use)
AMD A6-3500 CPU
4Gb RAM

What else you need to know?

Using a usb to external 2,5" HDD

please see attached screen cap for all the drives.

any suggestions peeps?

not sure if this will help, dm-0 is my lvm device:

mdadm --examine /dev/dm-0 
/dev/dm-0:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : 0f48d25d:a111a92a:a0b6e461:510ca67c
           Name : nas:RAID  (local to host nas)
  Creation Time : Tue Aug 12 20:28:25 2014
     Raid Level : raid5
   Raid Devices : 4


 Avail Dev Size : 3907041280 (1863.02 GiB 2000.41 GB)
     Array Size : 11721071616 (5589.04 GiB 6001.19 GB)
  Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
          State : clean
    Device UUID : 717deee1:a49ba6c2:b1449820:98cb6e76


    Update Time : Thu Aug 14 09:59:44 2014
       Checksum : 44269598 - correct
         Events : 23300


         Layout : left-symmetric
     Chunk Size : 512K


   Device Role : Active device 0
   Array State : AAAA ('A' == active, '.' == missing)

<p>Hi Tekkbebe</p>

<p>&nbsp;</p>

<p>Doesnt seem to be the issue, it is very short and simple.</p>

<p>As you can see everything seems to be in order, no errors anywhere, it just doesnt appear in the array for some reason?</p>

<p>&nbsp;</p>

<p>I am considering shrinking the array to just 3 x 2tb and then adding another 3 x 1tb array, then LVM on top of that.</p>

<p>&nbsp;</p>

<p>&nbsp;</p>

ok, so i am in the middle of shrinking the array, then will create 2 separate ones as David suggest in another post of my originally (should have taken your advice off the bat, but didnt want to lose that last TB).