利用mdadm工具构建RAID 0 1 5 6 10磁盘阵列实战（超详细）_mdadm raid5 重构

       Version : 1.2
 Creation Time : Tue Apr 21 15:55:29 2020
    Raid Level : raid0
    Array Size : 41906176 (39.96 GiB 42.91 GB)
  Raid Devices : 2
 Total Devices : 2
   Persistence : Superblock is persistent

   Update Time : Tue Apr 21 15:55:29 2020
         State : clean 
Active Devices : 2

Working Devices : 2
Failed Devices : 0
Spare Devices : 0

    Chunk Size : 512K

Consistency Policy : none

          Name : localhost.localdomain:0  (local to host localhost.localdomain)
          UUID : 4b439b50:63314c34:0fb14c51:c9930745
        Events : 0

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

2.格式化分区

[root@localhost ~]# mkfs.xfs /dev/md0
meta-data=/dev/md0 isize=512 agcount=16, agsize=654720 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=10475520, imaxpct=25
= sunit=128 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=5120, version=2
= sectsz=512 sunit=8 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

[root@localhost ~]# blkid /dev/md0
/dev/md0: UUID=“13a0c896-5e79-451f-b6f1-b04b79c1bc40” TYPE=“xfs”

3.格式化后挂载

[root@localhost ~]# mkdir /raid0 //创建挂载目录

[root@localhost ~]# mount /dev/md0 /raid0/ //将/dev/md0挂载到/raid0

[root@localhost ~]# df -h //查看挂载是否成功
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/centos-root 17G 11G 6.7G 61% /
devtmpfs 1.1G 0 1.1G 0% /dev
tmpfs 1.1G 0 1.1G 0% /dev/shm
…
/dev/md0 40G 33M 40G 1% /raid0

## RAID 1 实验


1.创建RAID 1

[root@localhost ~]# mdadm -C -v /dev/md1 -l 1 -n 2 /dev/sdd1 /dev/sde1 -x 1 /dev/sdb1
//在/dev/md1目录下将sdd1与sde1两块磁盘创建为RAID级别为1，磁盘数为2
的RAID1磁盘阵列并将sdd1作为备用磁盘

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: /dev/sdb1 appears to be part of a raid array:
level=raid0 devices=2 ctime=Tue Apr 21 15:55:29 2020
mdadm: size set to 20953088K
Continue creating array? y
mdadm: Fail create md1 when using /sys/module/md_mod/parameters/new_array
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.

2.查看RAID 1状态

[root@localhost ~]# cat /proc/mdstat
Personalities : [raid0] [raid1]
md1 : active raid1 sdb12 sde1[1] sdd1[0]
20953088 blocks super 1.2 [2/2] [UU]
[==========>…] resync = 54.4% (11407360/20953088) finish=0.7min speed=200040K/sec

unused devices:

[root@localhost ~]# mdadm -D /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Tue Apr 21 16:11:16 2020
Raid Level : raid1
Array Size : 20953088 (19.98 GiB 21.46 GB)
Used Dev Size : 20953088 (19.98 GiB 21.46 GB)
Raid Devices : 2
Total Devices : 3
Persistence : Superblock is persistent

   Update Time : Tue Apr 21 16:12:34 2020
         State : clean, resyncing 
Active Devices : 2

Working Devices : 3
Failed Devices : 0
Spare Devices : 1

Consistency Policy : resync

 Resync Status : 77% complete

          Name : localhost.localdomain:1  (local to host localhost.localdomain)
          UUID : 98b76e6e:b6390011:26a822a8:3dcc4cc9
        Events : 12

Number   Major   Minor   RaidDevice State
   0       8       49        0      active sync   /dev/sdd1
   1       8       65        1      active sync   /dev/sde1

   2       8       17        -      spare   /dev/sdb1

3.格式化并挂载

[root@localhost ~]# mkfs.xfs /dev/md1

[root@localhost ~]# blkid /dev/md1
/dev/md1: UUID=“18a8f33b-1bb6-43c2-8dfc-2b21a871961a” TYPE=“xfs”

[root@localhost ~]# mkdir /raid1

[root@localhost ~]# mount /dev/md1 /raid1/

[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/centos-root 17G 11G 6.7G 61% /
…
/dev/md1 20G 33M 20G 1% /raid1

## 4.模拟磁盘损坏


模拟损坏后查看RAID1阵列详细信息，发现/dev/sdb1自动替换了损坏的/dev/sdd1磁盘。

[root@localhost ~]# mdadm /dev/md1 -f /dev/sdd1

[root@localhost ~]# mdadm -D /dev/md1 //查看
/dev/md1: