RAID5 does not show-up and can't be recovered after disk change

Hi,

I am running OMV6, with a RAID 5 volume of 4 2TB disks.

As my RAID volume is 80% full, I'd like to extend its capacity; my plan is to swap progressively each 2TB disk by a new 4TB disk. I would expect the RAID to go into degraded mode, to recover with the new 4TB disk so it is added in the grap; when the RAID is recovered, then I swap the next 2TB disk and so on... Utilmately, mdadm shall manage actually 4 disks of 4TB and I will enjoy larger space for my RAID5 volume.

Unfortunately, when I swap the first 2TB disk with the new 4TB disk, the RAID5 is not mounted in OMV (FYI, I have formatted EXT4 then wiped the new 4TB disk prior to this operation, and it's clean). Moreover, I have no possibility to recover the RAID5; the button "Recover" is greyed out in the OMV interface, menu "RAID".

This is the status of my volume:

mdadm -vQD /dev/md127
/dev/md127:
           Version : 1.2
        Raid Level : raid0
     Total Devices : 3
       Persistence : Superblock is persistent

             State : inactive
   Working Devices : 3

              Name : GemenosNAS:Gemenos
              UUID : 5e222c44:31a161c4:3899a442:92cbf54f
            Events : 2238

    Number   Major   Minor   RaidDevice

       -       8       32        -        /dev/sdc
       -       8       48        -        /dev/sdd
       -       8       16        -        /dev/sdb

We can see that 3 of the 4 disks of my RAID5 are still attached, so I don't understand why I can't recover by adding the new 4TB disk.

When I reconnect my old 2TB disk, the RAID5 mounts properly.

I didn't find any similar issue in the forum.

Any help would be appreciated!

Regards

Oh my god...

That's was the issue; I can swap the disk now and it is under recovery.

Thank you for your prompt help!