mdadm DegradedArray，該軟體是問題還是硬體缺陷？

在主機的專用伺服器上，我收到了所有 raid 陣列 md0/md1/md2 的電子郵件：

This is an automatically generated mail message from mdadm running on cn.com
> `This is an automatically generated mail message from mdadm running on
> example.com
> 
> A DegradedArray event had been detected on md device /dev/md/2.
> 
> Faithfully yours, etc.
> 
> P.S. The /proc/mdstat file currently contains the following:
> 
> Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5]
> [raid4] [raid10] md2 : active raid1 nvme0n1p3[0]
>       903479616 blocks super 1.2 [2/1] [U_]
>       bitmap: 7/7 pages [28KB], 65536KB chunk
> 
> md0 : active raid1 nvme0n1p1[0]
>       33520640 blocks super 1.2 [2/1] [U_]
>        md1 : active raid1 nvme0n1p2[0]
>       523264 blocks super 1.2 [2/1] [U_]
>        unused devices: <none> `

不知道這是raid同步問題還是硬碟真的有問題，希望Linux高手能幫幫我。

兩台 NVME 三星設備作為軟體 raid mdadm 執行。

$ fdisk -l
nvme1n1     259:0    0 894.3G  0 disk
├─nvme1n1p1 259:2    0    32G  0 part
├─nvme1n1p2 259:3    0   512M  0 part
└─nvme1n1p3 259:4    0 861.8G  0 part
nvme0n1     259:1    0 894.3G  0 disk
├─nvme0n1p1 259:5    0    32G  0 part
│ └─md0       9:0    0    32G  0 raid1 [SWAP]
├─nvme0n1p2 259:6    0   512M  0 part
│ └─md1       9:1    0   511M  0 raid1 /boot
└─nvme0n1p3 259:7    0 861.8G  0 part
  └─md2       9:2    0 861.6G  0 raid1 /

從列表中可以看出，nvme1n1 及其分區不在raid 組中。顯然，作業系統也辨識出了nvme1n1。

$ dmesg 
[ 7664.380493] pcieport 0000:00:1b.4: AER: Corrected error received: 0000:00:1b.4
[ 7664.380514] pcieport 0000:00:1b.4: AER: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID)
[ 7664.380795] pcieport 0000:00:1b.4: AER:   device [8086:a32c] error status/mask=00000001/00002000
[ 7664.381066] pcieport 0000:00:1b.4: AER:    [ 0] RxErr
[ 7664.780438] pcieport 0000:00:1b.4: AER: Corrected error received: 0000:00:1b.4
[ 7664.780459] pcieport 0000:00:1b.4: AER: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID)
[ 7664.780739] pcieport 0000:00:1b.4: AER:   device [8086:a32c] error status/mask=00000001/00002000
[ 7664.781011] pcieport 0000:00:1b.4: AER:    [ 0] RxErr

lspci向我展示了兩個 nvme 設備

$lspci
01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983
03:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983

檢查 mdadm 詳細資訊以獲取例如 md0。

mdadm -D /dev/md0
/dev/md0:
          Version : 1.2
    Creation Time : Sat Aug  7 19:34:45 2021
       Raid Level : raid1
       Array Size : 33520640 (31.97 GiB 34.33 GB)
    Used Dev Size : 33520640 (31.97 GiB 34.33 GB)
     Raid Devices : 2
    Total Devices : 1
      Persistence : Superblock is persistent

      Update Time : Fri Mar  4 17:42:37 2022
            State : clean, degraded
   Active Devices : 1
  Working Devices : 1
   Failed Devices : 0
    Spare Devices : 0

Consistency Policy : resync

             Name : rescue:0
             UUID : 2e61cb41:dee3a004:b12de575:72c13ed0
           Events : 46

   Number   Major   Minor   RaidDevice State
      0     259        2        0      active sync   /dev/nvme0n1p1
      -       0        0        1      removed

在這裡我看不到設備 /dev/nvme1n1p1。這對我意味著什麼？

我的 mdadm.conf 文件

# mdadm.conf
#
# !NB! Run update-initramfs -u after updating this file.
# !NB! This will ensure that initramfs has an uptodate copy.
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
#DEVICE partitions containers

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY /dev/md/0  metadata=1.2 UUID=2e61cb41:dee3a004:b12de575:72c13ed0 name=rescue:0
ARRAY /dev/md/1  metadata=1.2 UUID=455ba7de:599eb665:202c1fe8:33c709f4 name=rescue:1
ARRAY /dev/md/2  metadata=1.2 UUID=c1f88478:e4ed5e8d:56f296cc:38e97b8c name=rescue:2
ARRAY /dev/md/0  metadata=1.2 UUID=e8c8f0cb:91007124:62e03226:94a707dc name=rescue:0
ARRAY /dev/md/1  metadata=1.2 UUID=a335efb7:cc52634c:3221294c:e7feb748 name=rescue:1
ARRAY /dev/md/2  metadata=1.2 UUID=f2a13b49:17f5e812:8e7c5adf:3114a929 name=rescue:2

# This configuration was auto-generated on Sat, 07 Aug 2021 19:35:14 +0200 by mkconf

我希望你能幫幫我

這是硬體級別的故障。由於它是託管伺服器，請讓供應商更換故障設備。不要費心嘗試修復它，只需將其換掉即可。這就是你付出的代價。

• 您需要與託管服務提供商安排停機時間
• 確保他們 100% 確定哪個磁碟設備有故障（我之前曾從一個應該知道更好的供應商那裡換掉一個好的磁碟。幸運的是，我執行的是 RAID6 並且可以應對第二個“故障” )
• 如果可以的話，無論如何都要備份“以防萬一”，一切都會出錯。無論如何，您都應該進行備份，因此請多備一份

引用自：https://unix.stackexchange.com/questions/693042