RAID1 적합한 드라이브를 찾을 수 없습니다

RAID1으로 구성된 2개의 디스크가 있는 Synology NAS가 있습니다. 어떻게 든 RAID 어레이가 엉망이되었습니다.

무슨 일이 일어나고 있는지 조사하기 위해 2개의 디스크를 데스크탑 컴퓨터에 삽입했습니다.

# mdadm --examine /dev/sda5
/dev/sda5:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : 40c15541:61481857:5a3fdf04:765977cb
           Name : DiskStation:2
  Creation Time : Sat Jul 13 09:54:06 2013
     Raid Level : raid1
   Raid Devices : 2

 Avail Dev Size : 5851063680 (2790.00 GiB 2995.74 GB)
     Array Size : 2925531648 (2790.00 GiB 2995.74 GB)
  Used Dev Size : 5851063296 (2790.00 GiB 2995.74 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1968 sectors, after=384 sectors
          State : clean
    Device UUID : 90c7ae42:472940bf:72e32970:97629479

    Update Time : Mon Aug 10 15:57:32 2020
       Checksum : 81d9d2fc - correct
         Events : 2520428


   Device Role : spare
   Array State : .. ('A' == active, '.' == missing, 'R' == replacing)

# mdadm --examine /dev/sdb5
/dev/sdb5:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : 40c15541:61481857:5a3fdf04:765977cb
           Name : DiskStation:2
  Creation Time : Sat Jul 13 09:54:06 2013
     Raid Level : raid1
   Raid Devices : 2

 Avail Dev Size : 5851063680 (2790.00 GiB 2995.74 GB)
     Array Size : 2925531648 (2790.00 GiB 2995.74 GB)
  Used Dev Size : 5851063296 (2790.00 GiB 2995.74 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1968 sectors, after=384 sectors
          State : clean
    Device UUID : 5636b0cc:49a4b1a7:a45d99a5:61f45c5a

    Update Time : Mon Aug 10 15:49:07 2020
       Checksum : 8a86c7af - correct
         Events : 2520660


   Device Role : Active device 32768
   Array State : .. ('A' == active, '.' == missing, 'R' == replacing)

# mdadm --examine --scan
ARRAY /dev/md/2  metadata=1.2 UUID=40c15541:61481857:5a3fdf04:765977cb name=DiskStation:2
   spares=1

도움이 된다면:

# blkid

/dev/sda5: UUID="40c15541-6148-1857-5a3f-df04765977cb" UUID_SUB="90c7ae42-4729-40bf-72e3-297097629479" LABEL="DiskStation:2" TYPE="linux_raid_member" PARTUUID="7400fe20-3ab4-4859-aec1-798032c26554"
/dev/sdb5: UUID="40c15541-6148-1857-5a3f-df04765977cb" UUID_SUB="5636b0cc-49a4-b1a7-a45d-99a561f45c5a" LABEL="DiskStation:2" TYPE="linux_raid_member" PARTUUID="9e3fee94-5c3c-4946-a5da-fc689f3a1f7e"
[...]

배열을 조립하려고 하면 다음과 같습니다.

# mdadm --assemble -f -v /dev/md2 /dev/sda5 /dev/sdb5
mdadm: looking for devices for /dev/md2
mdadm: /dev/sda5 is identified as a member of /dev/md2, slot -1.
mdadm: /dev/sdb5 is identified as a member of /dev/md2, slot 32768.
mdadm: No suitable drives found for /dev/md2

# mdadm --detail /dev/md2 
/dev/md2:
           Version : 1.2
        Raid Level : raid0
     Total Devices : 2
       Persistence : Superblock is persistent

             State : inactive
   Working Devices : 2

              Name : DiskStation:2
              UUID : 40c15541:61481857:5a3fdf04:765977cb
            Events : 2520660

    Number   Major   Minor   RaidDevice

       -       8       21        -        /dev/sdb5
       -       8        5        -        /dev/sda5

또한 하나의 디스크로 어레이를 조립해 보았습니다.

# mdadm --assemble -f -v /dev/md2 /dev/sda5 
mdadm: looking for devices for /dev/md2 
mdadm: /dev/sda5 is identified as a member of /dev/md2, slot -1. 
mdadm: no uptodate device for slot 0 of /dev/md2 
mdadm: no uptodate device for slot 1 of /dev/md2 
mdadm: added /dev/sda5 to /dev/md2 as -1 
mdadm: /dev/md2 assembled from 0 drives and 1 spare - not enough to start the array

저는 RAID 전문가는 아니지만 이 슬롯은-1그리고32768옳지 않은 것 같습니다.

이것이 문제의 원인이 될 수 있습니까? 어떻게 고치나요?

추신: 단순화를 위해 디스크 /dev/md3에 똑같은 문제가 있는 다른 어레이의 존재를 생략했습니다.