I set up OMV yesterday with a RAID 5 made from 3 drives (sdb, sdc, and sdd). Today I started getting emails saying "A DegradedArray event had been detected on md device /dev/md0." It looks like sdb is offline or something. In the web GUI, under "Disks", all the drives are listed. But under "S.M.A.R.T." > "Devices", the status circle is greyed out for sdb. Under "RAID Management", sdb is no longer listed as one of the devices.
Back under SMART > Extended information, I see:
smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.14.0-0.bpo.3-amd64] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, http://www.smartmontools.org
Short INQUIRY response, skip product id
A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.
Any suggestions for what my next steps should be? Do I just assume the drive is bad and replace it, or are there other troubleshooting things I can do?
Here is the output from the commands we're supposed to include when posting:
root@HOSTNAME:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sdd[2] sdc[1]
7813774336 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [_UU]
bitmap: 30/30 pages [120KB], 65536KB chunk
unused devices: <none>
root@HOSTNAME:~# blkid
/dev/sda1: UUID="6ecaf974-e508-4b57-ac73-1c7c6d4db83a" TYPE="ext4" PARTUUID="9b1c85d3-01"
/dev/sda5: UUID="ee468e24-5325-433d-a0e2-c4f80b8d2c99" TYPE="swap" PARTUUID="9b1c85d3-05"
/dev/sdb: UUID="86de832d-1fd4-1c45-e2da-b489d50ca2b1" UUID_SUB="c533bbcb-888a-0e3b-7c65-91d287ffcc7f" LABEL="HOSTNAME:MainRAID" TYPE="linux_raid_member"
/dev/sdd: UUID="86de832d-1fd4-1c45-e2da-b489d50ca2b1" UUID_SUB="243ebd72-8da8-65c2-1555-2efe889aa20f" LABEL="HOSTNAME:MainRAID" TYPE="linux_raid_member"
/dev/md0: LABEL="MainFileSystem" UUID="93dbae66-16f3-4cb9-a5ea-9f427e85d562" TYPE="ext4"
/dev/sdc: UUID="86de832d-1fd4-1c45-e2da-b489d50ca2b1" UUID_SUB="0f30d9c1-3ca8-1e61-43d6-ed1fad23ca74" LABEL="HOSTNAME:MainRAID" TYPE="linux_raid_member"
root@HOSTNAME:~# fdisk -l | grep "Disk "
Disk /dev/sda: 111.8 GiB, 120034123776 bytes, 234441648 sectors
Disk identifier: 0x9b1c85d3
Disk /dev/sdb: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Disk /dev/sdd: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Disk /dev/sdc: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Disk /dev/md0: 7.3 TiB, 8001304920064 bytes, 15627548672 sectors
root@HOSTNAME:~# 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=HOSTNAME:MainRAID UUID=86de832d:1fd41c45:e2dab489:d50ca2b1
# instruct the monitoring daemon where to send mail alerts
MAILADDR email@example.com
MAILFROM rootroot@HOSTNAME:~# mdadm --detail --scan --verbose
ARRAY /dev/md0 level=raid5 num-devices=3 metadata=1.2 name=HOSTNAME:MainRAID UUID=86de832d:1fd41c45:e2dab489:d50ca2b1
devices=/dev/sdc,/dev/sdd