Can somebody help a Noob please?
By accident I stupidly followed an upgrade which ended up with me upgrading to version 4. I would be happy to downgrade back to 3.x if I can without wiping my Raid and getting it to work again as this has some data on it.
Currently I see the raid shown in the Raid management screen but not on the file systems where it just shows missing.
root@Hostname-NAS:~# cat /proc//mdstat
Personalities : [raid10] [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]
md0 : active (auto-read-only) raid10 sda[0] sde[4](S) sdd[3] sdc[2] sdb[1]
1953262592 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
unused devices: <none>
root@Hostname-NAS:~# blkid
/dev/sda: UUID="bb4a59c9-e27c-3eff-382f-ed361b1e9a26" UUID_SUB="a00e7c38-6750-8771-f57d-43475a3a6ad6" LABEL="openmediavault:Hostname" TYPE="linux_raid_member"
/dev/sdb: UUID="bb4a59c9-e27c-3eff-382f-ed361b1e9a26" UUID_SUB="8693c07f-25cb-4a75-7f14-c76119bb746c" LABEL="openmediavault:Hostname" TYPE="linux_raid_member"
/dev/sdc: UUID="bb4a59c9-e27c-3eff-382f-ed361b1e9a26" UUID_SUB="a0843881-b205-2390-e0df-001e9f6b6f15" LABEL="openmediavault:Hostname" TYPE="linux_raid_member"
/dev/sdd: UUID="bb4a59c9-e27c-3eff-382f-ed361b1e9a26" UUID_SUB="d1f5e392-25c6-2251-290b-d6325ba6ab79" LABEL="openmediavault:Hostname" TYPE="linux_raid_member"
/dev/sde: UUID="bb4a59c9-e27c-3eff-382f-ed361b1e9a26" UUID_SUB="ee42741b-6661-becc-b2e6-947c05ac5dad" LABEL="openmediavault:Hostname" TYPE="linux_raid_member"
/dev/sdf1: UUID="f71d3d0c-95e9-4ec8-99fa-65c708fc5b04" TYPE="ext4" PARTUUID="0009afc7-01"
/dev/sdf5: UUID="d98e379a-4c82-414e-b841-18c0010783bf" TYPE="swap" PARTUUID="0009afc7-05"
root@Hostname-NAS:~# fdisk -l | grep "Disk "
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk /dev/sdb: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk /dev/sdc: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk /dev/md0: 1.8 TiB, 2000140894208 bytes, 3906525184 sectors
Disk /dev/sdd: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk /dev/sde: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk /dev/sdf: 55.9 GiB, 60022480896 bytes, 117231408 sectors
Disk identifier: 0x0009afc7
root@Hostname-NAS:~# 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 spares=1 name=openmediavault:Hostname UUID=bb4a59c9:e27c3eff:382fed36:1b1e9a26
root@Hostname-NAS:~# dadm --detail --scan --verbos
-bash: dadm: command not found
root@Hostname-NAS:~# mdadm --detail --scan --verbose
ARRAY /dev/md0 level=raid10 num-devices=4 metadata=1.2 spares=1 name=openmediavault:Hostname UUID=bb4a59c9:e27c3eff:382fed36:1b1e9a26
devices=/dev/sda,/dev/sdb,/dev/sdc,/dev/sdd,/dev/sde
root@Hostname-NAS:~# modprobe raid10
root@Hostname-NAS:~# lsmod | grep raid
raid456 106496 0
async_raid6_recov 20480 1 raid456
async_memcpy 16384 2 raid456,async_raid6_recov
async_pq 16384 2 raid456,async_raid6_recov
async_xor 16384 3 async_pq,raid456,async_raid6_recov
async_tx 16384 5 async_xor,async_pq,raid456,async_memcpy,async_raid6_recov
raid6_pq 110592 4 async_pq,btrfs,raid456,async_raid6_recov
libcrc32c 16384 1 raid456
raid1 36864 0
raid0 20480 0
raid10 49152 1
md_mod 131072 6 raid1,raid10,multipath,linear,raid0,raid456
Adrian