Thecus N3200: fsck hangs. Is it possible to build a RAID-5 on an Ubuntu PC?

Question

RAID

There is a Thecus N3200, 3 x 1Tb WDC WD10EARX installed, RAID-5 is assembled.
One fine day (power failure) the RAID-a status changed to N/A. Thecus RAID tech support collected it, but when you run fsck, you get the following picture:

12:10:06: process known inodes and inode discovery - 587968 of 2371328 inodes done
12:10:06: Phase 3: elapsed time 1 day, 1 hour, 28 minutes, 54 seconds - processed 384 inodes per minute
12:10:06: Phase 3: 24% done - estimated remaining time 3 days, 5 hours, 17 minutes, 17 seconds

09:55:06: process known inodes and inode discovery - 587968 of 2371328 inodes done
09:55:06: Phase 3: elapsed time 5 days, 23 hours, 13 minutes, 54 seconds - processed 68 inodes per minute
09:55:06: Phase 3: 24% done - estimated remaining time 2 weeks, 4 days, 2 hours, 26 minutes, 4 seconds

Inodes done does not change, Estimated remaining time increases.
I connect the disks to the PC, load Ubuntu, the disks are visible

[email protected]:~# mdadm --misc --query --examine /dev/sda
/dev/sda:
   MBR Magic : aa55
Partition[0] :      4016187 sectors at           63 (type fd)
Partition[1] :   1948491720 sectors at      5028345 (type fd)
Partition[2] :      1012095 sectors at      4016250 (type 83)

[email protected]:~# mdadm --misc --query --examine /dev/sdb
/dev/sdb:
   MBR Magic : aa55
Partition[0] :      4016187 sectors at           63 (type fd)
Partition[1] :   1948491720 sectors at      5028345 (type fd)
Partition[2] :      1012095 sectors at      4016250 (type 83)

[email protected]:~# mdadm --misc --query --examine /dev/sdc
/dev/sdc:
   MBR Magic : aa55
Partition[0] :      4016187 sectors at           63 (type fd)
Partition[1] :   1948491720 sectors at      5028345 (type fd)
Partition[2] :      1012095 sectors at      4016250 (type 83)

We take UUID from blkid, create mdadm.conf:

[email protected]:~# blkid
/dev/loop0: TYPE="squashfs"
/dev/sdb1: UUID="b99fa176-e404-ab89-50bb-78f233016ee8" TYPE="linux_raid_member"
/dev/sdb2: UUID="c3d6733d-96a9-e49e-355d-6ff5c20a139b" TYPE="linux_raid_member"
/dev/sda1: UUID="b99fa176-e404-ab89-50bb-78f233016ee8" TYPE="linux_raid_member"
/dev/sda2: UUID="c3d6733d-96a9-e49e-355d-6ff5c20a139b" TYPE="linux_raid_member"
/dev/sdc1: UUID="b99fa176-e404-ab89-50bb-78f233016ee8" TYPE="linux_raid_member"
/dev/sdc2: UUID="c3d6733d-96a9-e49e-355d-6ff5c20a139b" TYPE="linux_raid_member"
/dev/sdd1: LABEL="MYLINUXLIVE" UUID="CE81-347F" TYPE="vfat"

[email protected]:~# cat /etc/mdadm/mdadm.conf
CREATE owner=root group=disk mode=0660 auto=yes
HOMEHOST <system>
MAILADDR root
DEVICE /dev/sdb2 /dev/sdc2 /dev/sda2
ARRAY /dev/md0 level=RAID5 UUID=c3d6733d-96a9-e49e-355d-6ff5c20a139b

I'm trying to build a RAID:

[email protected]:~# mdadm -A -v /dev/md0 --metadata=0.90
mdadm: looking for devices for /dev/md0
mdadm: no RAID superblock on /dev/sdb2
mdadm: no RAID superblock on /dev/sdc2
mdadm: no RAID superblock on /dev/sda2

What am I doing wrong?

Answer 1

83 partition type is usually a file system,
judging by the number of sectors, you have a raid on partition 1 and you collect on the second one, is this some kind of secret knowledge?