mdadm raid问题(可能已过时)，并试图将raid6挂载为raid1

Question

出现了一些未知的硬件问题，似乎所有4个硬盘都发生了脱机问题。一些电线和硬盘又回来了(？)现在有突袭问题了。

Raid不会启动

从3个驱动器组装而成的/dev/md/1--不足以启动数组而不干净

但麻烦的是，当它是raid 6时，它似乎被视为raid 1。一个由4个驱动器组成的raid 6阵列应该与任何一个驱动器都一样。

在保留数据的同时，有什么建议想让这件事再次发生吗？首先有什么非破坏性的选择吗？在我弄清楚为什么它似乎相信它的raid 1之前，我还在犹豫是否要动武。

         mdadm --examine /dev/sd[dcba]3 | egrep 'Event|/dev'
        /dev/sda3:
                 Events : 395
        /dev/sdb3:
                 Events : 318
        /dev/sdc3:
                 Events : 396
        /dev/sdd3:
                 Events : 396
    
    So not that out of sync right?
    
    mdadm --assemble --scan -o -u 69d7ed4a:8bbcae7b:7fddfd36:6f1fcf16  -v
    mdadm: /dev/sdd3 is identified as a member of /dev/md/1, slot 1.
    mdadm: /dev/sdc3 is identified as a member of /dev/md/1, slot 2.
    mdadm: /dev/sdb3 is identified as a member of /dev/md/1, slot 3.
    mdadm: /dev/sda3 is identified as a member of /dev/md/1, slot 0.
    mdadm: added /dev/sda3 to /dev/md/1 as 0
    mdadm: added /dev/sdc3 to /dev/md/1 as 2
    mdadm: added /dev/sdb3 to /dev/md/1 as 3 (possibly out of date)
    mdadm: added /dev/sdd3 to /dev/md/1 as 1
    mdadm: /dev/md/1 assembled from 3 drives - not enough to start the array while not clean - consider --force.

检查驱动器显示为raid6，而sdb3是唯一没有显示缺少驱动器的驱动器。

mdadm --examine /dev/sd[dcba]3
/dev/sda3:
          Magic : a92b4efc
        Version : 1.0
    Feature Map : 0x0
     Array UUID : 69d7ed4a:8bbcae7b:7fddfd36:6f1fcf16
           Name : 1
  Creation Time : Sat Nov 24 17:11:48 2018
     Raid Level : raid6
   Raid Devices : 4

 Avail Dev Size : 15624915112 sectors (7.28 TiB 8.00 TB)
     Array Size : 15624915072 KiB (14.55 TiB 16.00 TB)
  Used Dev Size : 15624915072 sectors (7.28 TiB 8.00 TB)
   Super Offset : 15624915368 sectors
   Unused Space : before=0 sectors, after=296 sectors
          State : clean
    Device UUID : 53fb577d:03e1050b:3ab8b5b3:d5574384

    Update Time : Fri Jun 19 05:45:13 2020
       Checksum : 22c600bb - correct
         Events : 395

         Layout : left-symmetric
     Chunk Size : 64K

   Device Role : Active device 0
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdb3:
          Magic : a92b4efc
        Version : 1.0
    Feature Map : 0x0
     Array UUID : 69d7ed4a:8bbcae7b:7fddfd36:6f1fcf16
           Name : 1
  Creation Time : Sat Nov 24 17:11:48 2018
     Raid Level : raid6
   Raid Devices : 4

 Avail Dev Size : 15624915112 sectors (7.28 TiB 8.00 TB)
     Array Size : 15624915072 KiB (14.55 TiB 16.00 TB)
  Used Dev Size : 15624915072 sectors (7.28 TiB 8.00 TB)
   Super Offset : 15624915368 sectors
   Unused Space : before=0 sectors, after=296 sectors
          State : clean
    Device UUID : ac920534:e5bc15e4:b2472221:ce16aa24

    Update Time : Fri Jun 19 05:32:52 2020
       Checksum : c05abf36 - correct
         Events : 318

         Layout : left-symmetric
     Chunk Size : 64K

   Device Role : Active device 3
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdc3:
          Magic : a92b4efc
        Version : 1.0
    Feature Map : 0x0
     Array UUID : 69d7ed4a:8bbcae7b:7fddfd36:6f1fcf16
           Name : 1
  Creation Time : Sat Nov 24 17:11:48 2018
     Raid Level : raid6
   Raid Devices : 4

 Avail Dev Size : 15624915112 sectors (7.28 TiB 8.00 TB)
     Array Size : 15624915072 KiB (14.55 TiB 16.00 TB)
  Used Dev Size : 15624915072 sectors (7.28 TiB 8.00 TB)
   Super Offset : 15624915368 sectors
   Unused Space : before=0 sectors, after=296 sectors
          State : active
    Device UUID : 665a7028:041ce9d4:45396f7e:e9f45574

    Update Time : Fri Jun 19 05:45:18 2020
       Checksum : 528db8f6 - correct
         Events : 396

         Layout : left-symmetric
     Chunk Size : 64K

   Device Role : Active device 2
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdd3:
          Magic : a92b4efc
        Version : 1.0
    Feature Map : 0x0
     Array UUID : 69d7ed4a:8bbcae7b:7fddfd36:6f1fcf16
           Name : 1
  Creation Time : Sat Nov 24 17:11:48 2018
     Raid Level : raid6
   Raid Devices : 4

 Avail Dev Size : 15624915112 sectors (7.28 TiB 8.00 TB)
     Array Size : 15624915072 KiB (14.55 TiB 16.00 TB)
  Used Dev Size : 15624915072 sectors (7.28 TiB 8.00 TB)
   Super Offset : 15624915368 sectors
   Unused Space : before=0 sectors, after=296 sectors
          State : active
    Device UUID : 9b1ebb07:6cf51bf4:b6a52bd7:e7beedf9

    Update Time : Fri Jun 19 05:45:18 2020
       Checksum : 2f5f8d02 - correct
         Events : 396

         Layout : left-symmetric
     Chunk Size : 64K

   Device Role : Active device 1
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)

使用智能all检查所有驱动器，没有发现任何问题。

Answer 1

我没有看到任何证据表明mdadm试图使用RAID 1。

我看到的是mdadm试图启动一个RAID 6，发现一个磁盘过期了，两个磁盘丢失了，并且相当合理地拒绝组装它。

如果您有一个过时的磁盘，并且它是RAID 6，那么您可能无法依赖这个集合中的任何内容。如果你有备份的话，是时候从备份恢复了。