RAID 1 degraded, no apparent reason, unit cannot reboot or shutdown, SMART looks fine for both HDDs

Hello, I am struggling with an issue that has just shown up, after having OMV run with no issues for quite a while.

All of the sudden, I cannot gain access to OMV from one Win7 computer. Win10 apparently works ok. When checking system status via GUI, I found that there were some pending updates, that I tried to run several times with no avail. Anyways, I was not quite concerned about the updates, so I kept searching for potential issues, and I found that even though the SMART HDD analysis looks fine, RAID status shows /dev/md0 active, degraded.
No clue about what led to this situation, as I have a UPS to avoid brownouts or any power loss.

cat /proc/mdstat

root@OMV:~# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb[0](F) sdc[1]
2930135360 blocks super 1.2 [2/1] [_U]
unused devices: <none>

root@OMV:~# fdisk -l | grep "Disk "
Disk /dev/md0 doesn't contain a valid partition table
Disk /dev/sdd doesn't contain a valid partition table
Disk /dev/sde doesn't contain a valid partition table
Disk /dev/sda: 160.0 GB, 160041885696 bytes
Disk identifier: 0x00071626
Disk /dev/md0: 3000.5 GB, 3000458608640 bytes
Disk identifier: 0x00000000
Disk /dev/sdd: 3000.6 GB, 3000592982016 bytes
Disk identifier: 0x00000000
Disk /dev/sde: 3000.6 GB, 3000592982016 bytes
Disk identifier: 0x00000000

root@OMV:~# cat /etc/mdadm/mdadm.conf
# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#
# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
# Note, if no DEVICE line is present, then "DEVICE partitions" is assumed.
# To avoid the auto-assembly of RAID devices a pattern that CAN'T match is
# used if no RAID devices are configured.
DEVICE partitions
# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes
# automatically tag new arrays as belonging to the local system
HOMEHOST <system>
# definitions of existing MD arrays
ARRAY /dev/md0 metadata=1.2 name=OMV:VolumeOne UUID=3dc20369:61bff7ce:f7e09590:7aee7194

root@OMV:~# mdadm --detail --scan --verbose
ARRAY /dev/md0 level=raid1 num-devices=2 metadata=1.2

I have two WD RED 3TB drives as well as a small Hitachi 150GB drive for OS

It looks pretty odd that I cannot reboot or shutdown the unit, either from the web GUI or using a terminal. I am not quite skilled on Linux, but I guess I know how to reboot or shutdown from command line.

Your guidance will be appreciated, as I have no idea about what is going on here.

Regards

Alberto

Hello, Thank you for the feedback.

I ran mdadm to no avail, as follows:

root@OMV:~# mdadm --stop /dev/md0
mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running process, mounted filesystem or active volume group?
root@OMV:~# sudo mdadm --stop /dev/md0
mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running process, mounted filesystem or active volume group?

In case I can somehow stop RAID, how can I identify the supposedly missing (damaged) drive to run next command? (the [ed] between brackets).

mdadm --assemble --force --verbose /dev/md0 /dev/sd[ed]

Thank you!

Alberto

Hello,

I tried umount:

root@OMV:~# umount /dev/md0
umount: /media/3156d0bd-44c3-4046-a2d0-ecf6331ef93f: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))

I guess the disks are ok, as you said on previous message. Once I get this thing back on track I will seriously evaluate whether keeping RAID or using mirroring as you propose. RAID seems to be more complex to fix in case things go wrong.

Regards

Alberto

OK, I was trying to avoid abrupt power off, but the system is not responding to either shutdown or reboot commands, no matter whether command is issued from CLI or GUI.

Should I just force power off?

Regards