RAID Array Missing

I set up a RAID 5 array using 4 disks on a NAS I use for manual backups. the disks included are sdb, sdc, sdd, and sde. I noted the NAS was not working and debugging in the webUI showed the RAID array to be missing and sdc to have bad sectors.

Digging a little further I've noted the following:

/etc/mdadm/mdadm.conf references /dev/md0

ARRAY /dev/md0 metadata=1.2 name=SPOT.local:mainarray UUID=53d92414:cab02b2d:ac3cc183:72749370

and mdadm examination of any of the disks shows

ARRAY /dev/md/mainarray metadata=1.2 UUID=53d92414:cab02b2d:ac3cc183:72749370 name=SPOT.local:mainarray

/dev/md/mainarray does not exist

/dev/md0 references a RAID 0 array with only sdb, sdd, and sde

I'm not super familiar with mdadm and linux arrays. Did the failure of sdc lead to the configuration file using /dev/md0 in place of /dev/md/mainarray?

How do I restart the array using the remaining disks?

attached:

raid.status (mdadm --examine /dev/sd[a-e] >> raid.status)

dmesg.log

mdadm.conf

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [ra                                                                                                                                                             id10]
md0 : inactive sdb[0](S) sdd[2](S) sde[3](S)
      11720659464 blocks super 1.2

/dev/md0:
           Version : 1.2
        Raid Level : raid0
     Total Devices : 3
       Persistence : Superblock is persistent

             State : inactive
   Working Devices : 3

              Name : SPOT.local:mainarray
              UUID : 53d92414:cab02b2d:ac3cc183:72749370
            Events : 14485

    Number   Major   Minor   RaidDevice

       -       8       64        -        /dev/sde
       -       8       48        -        /dev/sdd
       -       8       16        -        /dev/sdb

/dev/sdb:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : 53d92414:cab02b2d:ac3cc183:72749370
           Name : SPOT.local:mainarray
  Creation Time : Sat Dec  7 22:11:43 2019
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 7813772976 (3725.90 GiB 4000.65 GB)
     Array Size : 11720658432 (11177.69 GiB 12001.95 GB)
  Used Dev Size : 7813772288 (3725.90 GiB 4000.65 GB)
    Data Offset : 264192 sectors
   Super Offset : 8 sectors
   Unused Space : before=264112 sectors, after=688 sectors
          State : clean
    Device UUID : 52eff8bd:424cb5dc:5ee52009:d950e0c6

Internal Bitmap : 8 sectors from superblock
    Update Time : Mon Sep 20 21:02:18 2021
  Bad Block Log : 512 entries available at offset 24 sectors
       Checksum : ac088206 - correct
         Events : 14485

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 0
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)

I don't understand why the Raid Level for md0 is showing as raid0 as I know it was set up as raid5. The three functioning drives are showing Raid Level raid5.

Thanks! It looks like the drive failed (probably offline) and then during reboot the assembly generated a goofy setup?

I was a little hesitant about commands that would overwrite the raid configuration. But for future note I did run:

mdadm --stop /dev/md0

mdadm --assemble /dev/md0 /dev/sd[bde]

mdadm --run /dev/md0

(I would note I probably didn't need this command if I had run the assembly command with the '--force' option)

This got the RAID array back up in a "clean, degraded" state. After mounting it in the webUI, I was able to access the shared files systems again. The RAID and File System are persistent through reboot. (I'm going to assume the persistence is due to the failed hard drive no longer being in the array)

Waiting on a replacement drive, but glad I don't have to go through and restore the data from the original locations. I think there are plenty resources to add a replacement drive to a degraded RAID. Again thanks for the help!