Raid 5 （软raid）创建、模拟损坏、移除、添加新磁盘

2025年11月02日 14点热度 0人点赞 0条评论

1. 查看磁盘分区，做raid5 最少需要3块盘
2. 用mdadm 命令创建raid5 阵列
3. 查看raid5阵列信息，可以看到我们的raid5 已经创建完毕
4. 生成配置文件
5. 对其创建文件系统，在这里我选择的是xfs格式，并进行挂载操作
6. 挂载，并查看挂载状态
7. 开机自动挂载
8. 模拟硬盘损坏
9. 移除已失效的磁盘
10. 增加新的硬盘替换失效硬盘

1. 查看磁盘分区，做raid5 最少需要3块盘

lsblk[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 127G 0 disk
├─sda1 8:1 0 600M 0 part /boot/efi
├─sda2 8:2 0 1G 0 part /boot
└─sda3 8:3 0 125.4G 0 part
├─cs-root 253:0 0 70G 0 lvm /
├─cs-swap 253:1 0 7.9G 0 lvm [SWAP]
└─cs-home 253:2 0 47.5G 0 lvm /home
sdb 8:16 0 16G 0 disk
sdc 8:32 0 16G 0 disk
sdd 8:48 0 16G 0 disk
sde 8:64 0 16G 0 disk
sdf 8:80 0 16G 0 disk
sdg 8:96 0 16G 0 disk
sdh 8:112 0 16G 0 disk
sdi 8:128 0 16G 0 disk
sdj 8:144 0 16G 0 disk
sdk 8:160 0 16G 0 disk
sdl 8:176 0 16G 0 disk
sdm 8:192 0 16G 0 disk
sdn 8:208 0 16G 0 disk
sdo 8:224 0 16G 0 disk
sdp 8:240 0 16G 0 disk
sdq 65:0 0 16G 0 disk

2. 用mdadm 命令创建raid5 阵列

使用命令：mdadm --create /dev/md0 --level=5 --raid-devices=16 /dev/sd[b-q]

--create /dev/md0：创建
--level=5：raid 级别
--raid-devices=16：创建硬盘数量
/dev/sd[b-q]：指定硬盘

[root@localhost ~]# mdadm --create /dev/md0 --level=5 --raid-devices=16 /dev/sd[b-q]
To optimalize recovery speed, it is recommended to enable write-indent bitmap, do you want to enable it now? [y/N]? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

3. 查看raid5阵列信息，可以看到我们的raid5 已经创建完毕

[root@localhost ~]# mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Sun Nov  2 19:01:28 2025
        Raid Level : raid5
        Array Size : 251397120 (239.75 GiB 257.43 GB)
     Used Dev Size : 16759808 (15.98 GiB 17.16 GB)
      Raid Devices : 16
     Total Devices : 16
       Persistence : Superblock is persistent

     Intent Bitmap : Internal

       Update Time : Sun Nov  2 19:02:35 2025
             State : clean, degraded, recovering
    Active Devices : 15
   Working Devices : 16
    Failed Devices : 0
     Spare Devices : 1

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : bitmap

    Rebuild Status : 80% complete

              Name : localhost.localdomain:0  (local to host localhost.localdomain)
              UUID : b45e6239:f4321e20:c0058af8:2d9f7133
            Events : 18

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       1       8       32        1      active sync   /dev/sdc
       2       8       48        2      active sync   /dev/sdd
       3       8       64        3      active sync   /dev/sde
       4       8       80        4      active sync   /dev/sdf
       5       8       96        5      active sync   /dev/sdg
       6       8      112        6      active sync   /dev/sdh
       7       8      128        7      active sync   /dev/sdi
       8       8      144        8      active sync   /dev/sdj
       9       8      160        9      active sync   /dev/sdk
      10       8      176       10      active sync   /dev/sdl
      11       8      192       11      active sync   /dev/sdm
      12       8      208       12      active sync   /dev/sdn
      13       8      224       13      active sync   /dev/sdo
      14       8      240       14      active sync   /dev/sdp
      16      65        0       15      spare rebuilding   /dev/sdq

等所有硬盘状态从 rebuilding 变成 sync ，就完成了raid5创建

4. 生成配置文件

mdadm -Ds > /etc/mdadm.conf

如没这一步，重启后 /dev/md0 会变成 /dev/md127

dracut -f

（CentOS/RHEL系统）更新初始化内存文件系统，确保配置生效。

5. 对其创建文件系统，在这里我选择的是xfs格式，并进行挂载操作

[root@localhost ~]# mkfs.xfs -f /dev/md0
meta-data=/dev/md0 isize=512 agcount=16, agsize=3928192 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=0
data = bsize=4096 blocks=62849280, imaxpct=25
= sunit=128 swidth=1920 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=0
log =internal log bsize=4096 blocks=30688, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

6. 挂载，并查看挂载状态

[root@localhost ~]# mount /dev/md0 /mnt/md0/ [root@localhost ~]# df -Th Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/cs-root xfs 70G 2.6G 68G 4% / devtmpfs devtmpfs 7.7G 0 7.7G 0% /dev tmpfs tmpfs 7.7G 0 7.7G 0% /dev/shm efivarfs efivarfs 128M 34K 128M 1% /sys/firmware/efi/efivars tmpfs tmpfs 3.1G 11M 3.1G 1% /run tmpfs tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-journald.service /dev/sdb2 xfs 960M 229M 732M 24% /boot /dev/mapper/cs-home xfs 48G 964M 47G 2% /home /dev/sdb1 vfat 599M 8.4M 591M 2% /boot/efi tmpfs tmpfs 1.0M 0 1.0M 0% /run/credentials/getty@tty1.service tmpfs tmpfs 1.6G 4.0K 1.6G 1% /run/user/1000 /dev/md0 xfs 240G 4.7G 236G 2% /mnt/md0

7. 开机自动挂载

先查找分区UUID

[root@localhost ~]# ls -all /dev/disk/by-uuid/
total 0
drwxr-xr-x. 2 root root 160 Nov  2 19:33 .
drwxr-xr-x. 8 root root 160 Nov  2 19:31 ..
lrwxrwxrwx. 1 root root  10 Nov  2 19:31 4de6582e-75ce-41cd-b462-f45d7ed9e4c5 -> ../../dm-1
lrwxrwxrwx. 1 root root  10 Nov  2 19:31 62904add-ac26-4681-9f56-58262ed9ce5c -> ../../dm-0
lrwxrwxrwx. 1 root root  10 Nov  2 19:31 7a099979-69c5-4a64-a5d1-102fcb527d6d -> ../../dm-2
lrwxrwxrwx. 1 root root   9 Nov  2 19:33 8d4bd631-43fd-497a-a24c-63350fb03a73 -> ../../md0
lrwxrwxrwx. 1 root root  10 Nov  2 19:31 aeaca083-477c-4b98-948b-4270cf7431ec -> ../../sdb2
lrwxrwxrwx. 1 root root  10 Nov  2 19:31 D110-1DEC -> ../../sdb1

其中 ../../md0 为刚才格式化的分区，将UUID增加到 fstab 文件

UUID=8d4bd631-43fd-497a-a24c-63350fb03a73 /data xfs defaults 1 2

/data 为分区挂载目录，修改成自己想要的路径。重启，查看挂载是否成功。

[root@localhost ~]# df -Th
Filesystem          Type      Size  Used Avail Use% Mounted on
/dev/mapper/cs-root xfs        70G  2.6G   68G   4% /
devtmpfs            devtmpfs  7.7G     0  7.7G   0% /dev
tmpfs               tmpfs     7.7G     0  7.7G   0% /dev/shm
efivarfs            efivarfs  128M   34K  128M   1% /sys/firmware/efi/efivars
tmpfs               tmpfs     3.1G   11M  3.1G   1% /run
tmpfs               tmpfs     1.0M     0  1.0M   0% /run/credentials/systemd-journald.service
/dev/sda2           xfs       960M  229M  732M  24% /boot
/dev/sda1           vfat      599M  8.4M  591M   2% /boot/efi
/dev/mapper/cs-home xfs        48G  964M   47G   2% /home
/dev/md0            xfs       240G  4.7G  236G   2% /data
tmpfs               tmpfs     1.0M     0  1.0M   0% /run/credentials/getty@tty1.service
tmpfs               tmpfs     1.6G  4.0K  1.6G   1% /run/user/1000

8. 模拟硬盘损坏

先将目标磁盘从阵列中标记为失效，避免数据不一致：

[root@localhost ~]# mdadm --manage /dev/md0 --fail /dev/sdc
[root@localhost ~]# mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Sun Nov  2 19:26:11 2025
        Raid Level : raid5
        Array Size : 251397120 (239.75 GiB 257.43 GB)
     Used Dev Size : 16759808 (15.98 GiB 17.16 GB)
      Raid Devices : 16
     Total Devices : 16
       Persistence : Superblock is persistent

     Intent Bitmap : Internal

       Update Time : Sun Nov  2 19:40:45 2025
             State : clean, degraded
    Active Devices : 15
   Working Devices : 15
    Failed Devices : 1
     Spare Devices : 0

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : bitmap

              Name : localhost.localdomain:0  (local to host localhost.localdomain)
              UUID : ca39bc78:c9f823e7:91cf7d03:2f2d5856
            Events : 31

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       -       0        0        1      removed
       2       8       48        2      active sync   /dev/sdd
       3       8      176        3      active sync   /dev/sdl
       4       8       96        4      active sync   /dev/sdg
       5       8       64        5      active sync   /dev/sde
       6       8       80        6      active sync   /dev/sdf
       7       8      224        7      active sync   /dev/sdo
       8       8      144        8      active sync   /dev/sdj
       9       8      112        9      active sync   /dev/sdh
      10       8      128       10      active sync   /dev/sdi
      11       8      192       11      active sync   /dev/sdm
      12       8      160       12      active sync   /dev/sdk
      13       8      208       13      active sync   /dev/sdn
      14       8      240       14      active sync   /dev/sdp
      16      65        0       15      active sync   /dev/sdq

       1       8       32        -      faulty   /dev/sdc

可看到 /dev/sdc 状态变成了 faulty

9. 移除已失效的磁盘

[root@localhost ~]# mdadm --manage /dev/md0 --remove /dev/sdc
mdadm: hot removed /dev/sdc from /dev/md0
[root@localhost ~]# mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Sun Nov  2 19:26:11 2025
        Raid Level : raid5
        Array Size : 251397120 (239.75 GiB 257.43 GB)
     Used Dev Size : 16759808 (15.98 GiB 17.16 GB)
      Raid Devices : 16
     Total Devices : 15
       Persistence : Superblock is persistent

     Intent Bitmap : Internal

       Update Time : Sun Nov  2 19:42:05 2025
             State : clean, degraded
    Active Devices : 15
   Working Devices : 15
    Failed Devices : 0
     Spare Devices : 0

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : bitmap

              Name : localhost.localdomain:0  (local to host localhost.localdomain)
              UUID : ca39bc78:c9f823e7:91cf7d03:2f2d5856
            Events : 32

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       -       0        0        1      removed
       2       8       48        2      active sync   /dev/sdd
       3       8      176        3      active sync   /dev/sdl
       4       8       96        4      active sync   /dev/sdg
       5       8       64        5      active sync   /dev/sde
       6       8       80        6      active sync   /dev/sdf
       7       8      224        7      active sync   /dev/sdo
       8       8      144        8      active sync   /dev/sdj
       9       8      112        9      active sync   /dev/sdh
      10       8      128       10      active sync   /dev/sdi
      11       8      192       11      active sync   /dev/sdm
      12       8      160       12      active sync   /dev/sdk
      13       8      208       13      active sync   /dev/sdn
      14       8      240       14      active sync   /dev/sdp
      16      65        0       15      active sync   /dev/sdq

可见 /dev/sdc Number变成了-，状态变成了 removed，从阵列中移除了。

10. 增加新的硬盘替换失效硬盘

[root@localhost ~]# mdadm --manage /dev/md0 --add /dev/sdc
mdadm: re-added /dev/sdc
[root@localhost ~]# mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Sun Nov  2 19:26:11 2025
        Raid Level : raid5
        Array Size : 251397120 (239.75 GiB 257.43 GB)
     Used Dev Size : 16759808 (15.98 GiB 17.16 GB)
      Raid Devices : 16
     Total Devices : 16
       Persistence : Superblock is persistent

     Intent Bitmap : Internal

       Update Time : Sun Nov  2 19:53:50 2025
             State : clean
    Active Devices : 16
   Working Devices : 16
    Failed Devices : 0
     Spare Devices : 0

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : bitmap

              Name : localhost.localdomain:0  (local to host localhost.localdomain)
              UUID : ca39bc78:c9f823e7:91cf7d03:2f2d5856
            Events : 50

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       1       8       32        1      active sync   /dev/sdc
       2       8       48        2      active sync   /dev/sdd
       3       8       80        3      active sync   /dev/sdf
       4       8       64        4      active sync   /dev/sde
       5       8       96        5      active sync   /dev/sdg
       6       8      128        6      active sync   /dev/sdi
       7       8      160        7      active sync   /dev/sdk
       8       8      176        8      active sync   /dev/sdl
       9       8      112        9      active sync   /dev/sdh
      10       8      144       10      active sync   /dev/sdj
      11       8      208       11      active sync   /dev/sdn
      12       8      192       12      active sync   /dev/sdm
      13       8      224       13      active sync   /dev/sdo
      14      65        0       14      active sync   /dev/sdq
      16       8      240       15      active sync   /dev/sdp

添加新硬盘后阵列会自动同步数据