模拟RAID1磁盘阵列搭建

1、恢复环境

（1）、删除/etc/fstab配置文件中自动挂载记录

删除的内容如下：

/dev/md0p1 /mnt/md0 xfs defaults 0 0

（2）、解除挂载

# umount /mnt/md0

（3）、停止md0的运行

# mdadm -S /dev/md0

[root@localhost ~]# mdadm -S /dev/md0
mdadm: stopped /dev/md0

查看磁盘信息

# lsblk

[root@localhost ~]# lsblk 
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   50G  0 disk 
├─sda1            8:1    0  500M  0 part /boot
└─sda2            8:2    0   49G  0 part 
  ├─centos-root 253:0    0   41G  0 lvm  /
  └─centos-swap 253:1    0    8G  0 lvm  [SWAP]
sdb               8:16   0   10G  0 disk 
└─sdb1            8:17   0   10G  0 part 
sdc               8:32   0   10G  0 disk 
└─sdc1            8:33   0   10G  0 part 
sr0              11:0    1  4.2G  0 rom

（4）、删除RAID 0

清除组件设备sdb1中超级块的信息

# mdadm --zero-superblock /dev/sdb1

清除组件设备sdc1中超级块的信息

# mdadm --zero-superblock /dev/sdc1

2、创建RAID 1

创建一个md1，指定设备数为2个，分别为sdb1、sdc1

# mdadm -C -v /dev/md1 -l 1 -n 2 /dev/sdb1 /dev/sdc1

[root@localhost ~]# mdadm -C -v /dev/md1 -l 1 -n 2 /dev/sdb1 /dev/sdc1
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: size set to 10475520K
Continue creating array? y
mdadm: Fail to create md1 when using /sys/module/md_mod/parameters/new_array, fallback to creation via node
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.

查看结果

# lsblk

[root@localhost ~]# lsblk 
NAME            MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sda               8:0    0   50G  0 disk  
├─sda1            8:1    0  500M  0 part  /boot
└─sda2            8:2    0   49G  0 part  
  ├─centos-root 253:0    0   41G  0 lvm   /
  └─centos-swap 253:1    0    8G  0 lvm   [SWAP]
sdb               8:16   0   10G  0 disk  
└─sdb1            8:17   0   10G  0 part  
  └─md1           9:1    0   10G  0 raid1 
    └─md1p1     259:0    0   10G  0 md    
sdc               8:32   0   10G  0 disk  
└─sdc1            8:33   0   10G  0 part  
  └─md1           9:1    0   10G  0 raid1 
    └─md1p1     259:0    0   10G  0 md    
sr0              11:0    1  4.2G  0 rom

3、查看/dev/md1 信息

# mdadm -D /dev/md1

[root@localhost ~]# mdadm -D /dev/md1
/dev/md1:
           Version : 1.2
     Creation Time : Sat Aug  7 23:37:19 2021
        Raid Level : raid1
        Array Size : 10475520 (9.99 GiB 10.73 GB)
     Used Dev Size : 10475520 (9.99 GiB 10.73 GB)
      Raid Devices : 2
     Total Devices : 2
       Persistence : Superblock is persistent

       Update Time : Sat Aug  7 23:38:11 2021
             State : clean 
    Active Devices : 2
   Working Devices : 2
    Failed Devices : 0
     Spare Devices : 0

Consistency Policy : unknown

              Name : localhost.localdomain:1  (local to host localhost.localdomain)
              UUID : e79afe8f:78e892b6:9ee993ca:7a742a92
            Events : 17

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1

4、格式化

# mkfs.xfs /dev/md1p1

[root@localhost ~]# mkfs.xfs /dev/md1p1
meta-data=/dev/md1p1             isize=256    agcount=4, agsize=654656 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=2618624, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

5、挂载

创建一个挂载目录

# mkdir /mnt/md1

挂载

# mount /dev/md1p1 /mnt/md1

6、查看挂载信息

# df -Th

[root@localhost ~]# df -Th
文件系统                类型      容量  已用  可用 已用% 挂载点
/dev/mapper/centos-root xfs        41G  1.5G   40G    4% /
devtmpfs                devtmpfs  1.9G     0  1.9G    0% /dev
tmpfs                   tmpfs     1.9G     0  1.9G    0% /dev/shm
tmpfs                   tmpfs     1.9G  8.6M  1.9G    1% /run
tmpfs                   tmpfs     1.9G     0  1.9G    0% /sys/fs/cgroup
/dev/sda1               xfs       497M  150M  348M   31% /boot
tmpfs                   tmpfs     378M     0  378M    0% /run/user/0
/dev/md1p1              xfs        10G   33M   10G    1% /mnt/md1

7、查看内存中md驱动的状态

# cat /proc/mdstat

[root@localhost ~]# cat /proc/mdstat 
Personalities : [raid1] 
md1 : active raid1 sdc1[1] sdb1[0]
      10475520 blocks super 1.2 [2/2] [UU]
      
unused devices: <none>