我的操作系统是 Ubuntu 12.04.2 LTS，内核为：3.2.0-49-generic #75-Ubuntu SMP Tue Jun 18 17:39:32 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
我有一个由 3 个硬盘组成的 raid 5 阵列，突然，它在启动时开始处于非活动状态。由于主目录安装在其上，系统无法启动，并要求用户手动干预。我在论坛上发现了类似的报告，但其中大多数恰好有一个有缺陷的硬盘，而我的情况并非如此。
停止阵列（mdadm --stop /dev/md0）并重新启动（mdadm --assemble --scan /dev/md0）没有显示任何错误（没有抱怨或阵列重建）然后它可以正确安装（手动安装）那么为什么它不能在启动时启动？
在检查组成 raid 阵列的所有硬盘（sda、sdb、sdc）的 smartctl 后，我没有发现任何错误（无 Current_Pending_Sector、UDMA_CRC_Error_Count、Offline_Uncorrectable）。已经进行了短期和长期测试。
我注意到的一件事，也是问题的主要原因是 grub-probe 返回此错误：“错误：为 RAID md/0 找到两个索引为 1 的磁盘。”
使用 -v（详细输出）运行相同的命令，在探测 hd0 和 hd1 之后，我可以看到两行注释“grub-probe：info：找到阵列 md/0 (mdraid1x)。”，这两个阵列分别映射到 sda 和 sdb 上。那么 sdc 没有 grub 可读的 raid 元数据吗？遇到此问题的人建议将 raid 元数据从 0.90 更新到 1.x，但我的 raid 已经在使用 1.2 了。
我尝试手动让 sdc 硬盘发生故障两次（第一次只是将其移除并重新添加，第二次使用 mdadm --zero-superblock /dev/sdc）并强制重建 raid，但错误无法消失，所以我现在陷入困境。有人知道问题可能是什么以及如何修复吗？
下面是我用来诊断问题的命令及其输出列表：
启动后 /proc/stat
# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : inactive sdc1[3](S) sda1[4](S) sdb[5](S)
5860540617 blocks super 1.2
unused devices: <none>
/etc/mdadm/mdadm.conf
# cat /etc/mdadm/mdadm.conf
# mdadm.conf
#
# 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
# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes
# 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=1b273efc:62f3bc36:4579f11d:15bbc75e name=ubuntu:0
# This file was auto-generated on Mon, 27 Aug 2012 17:33:16 +0300
# by mkconf $Id$
mdadm --检查 --扫描
# mdadm --examine --scan
ARRAY /dev/md/0 metadata=1.2 UUID=1b273efc:62f3bc36:4579f11d:15bbc75e name=ubuntu:0
mdadm --detail
# mdadm --detail --scan
mdadm: cannot open /dev/md/0: No such file or directory
# mdadm --detail --scan /dev/md0
mdadm: md device /dev/md0 does not appear to be active.
mdadm --stop /dev/md0 && mdadm --assemble --scan /dev/md0 && mdadm --detail /dev/md0
# mdadm --stop /dev/md0
mdadm: stopped /dev/md0
# mdadm --assemble --scan /dev/md0
mdadm: /dev/md0 has been started with 3 drives.
# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sda1[4] sdc1[3] sdb1[5]
3907025920 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
unused devices: <none>
# mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Sat Mar 24 15:31:43 2012
Raid Level : raid5
Array Size : 3907025920 (3726.03 GiB 4000.79 GB)
Used Dev Size : 1953512960 (1863.02 GiB 2000.40 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sun Jul 21 22:53:21 2013
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : ubuntu:0
UUID : 1b273efc:62f3bc36:4579f11d:15bbc75e
Events : 319386
Number Major Minor RaidDevice State
4 8 1 0 active sync /dev/sda1
5 8 17 1 active sync /dev/sdb1
3 8 33 2 active sync /dev/sdc1
mdadm --detail --scan && mdadm --examine --scan
# mdadm --detail --scan
ARRAY /dev/md0 metadata=1.2 name=ubuntu:0 UUID=1b273efc:62f3bc36:4579f11d:15bbc75e
# mdadm --examine --scan
ARRAY /dev/md/0 metadata=1.2 UUID=1b273efc:62f3bc36:4579f11d:15bbc75e name=ubuntu:0
grub-probe -v /
# grub-probe -v /
grub-probe: info: cannot open `/boot/grub/device.map'.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: scanning hd1 for LVM.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: scanning hd2 for LVM.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: scanning hd3 for LVM.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Found array md/0 (mdraid1x).
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos1.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos1.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos2.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos1.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos1.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: Found array md/0 (mdraid1x).
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos1.
grub-probe: info: the size of hd1 is 3907029168.
error: found two disks with the index 1 for RAID md/0.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos1.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos2.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos1.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: scanning md/0 for LVM.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: scanning hd0,msdos1 for LVM.
grub-probe: info: the size of hd0 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd1 for LVM.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: scanning hd1,msdos1 for LVM.
grub-probe: info: the size of hd1 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd2 for LVM.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: scanning hd2,msdos1 for LVM.
grub-probe: info: the size of hd2 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd3 for LVM.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: scanning hd3,msdos2 for LVM.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd3,msdos1 for LVM.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: no LVM signature found.
grub-probe: info: /dev/sdd1 starts from 2048.
grub-probe: info: opening the device hd3.
grub-probe: info: the size of hd3 is 250069680.
grub-probe: info: Partition 0 starts from 2048.
grub-probe: info: opening hd3,msdos1.
grub-probe: info: the size of hd3 is 250069680.
ext2
/boot/grub/设备映射
# cat /boot/grub/device.map
(hd0) /dev/sda
(hd1) /dev/sdb
(hd2) /dev/sdc
(hd3) /dev/sdd
答案1
我通过移除 raid 中的每个磁盘（逐个），将超级块和 MBR 归零，将它们添加回 raid 并等待重建来解决问题。
在我对 /dev/sdb 执行上述操作之后，问题就解决了，现在 grub-probe 只显示一行“grub-probe：info：找到数组 md/0（mdraid1x）。”，而不是像以前那样显示两行（看看问题）。
因此，它肯定与我最初关于索引错误的想法相反。我的想法是，这个索引应该存在于 raid 的每个磁盘中，这就是为什么我擦除 sdc 而 grub-probe 没有显示任何“grub-probe：信息：找到阵列 md/0 (mdraid1x)。”消息。
最终看起来只有其中一个必须拥有它，并且如果它在多个硬盘中，则会出现此错误“错误：为 RAID md/0 找到两个索引为 1 的磁盘”。