6-3、停止磁盘阵列（--stop）

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

mdadm: stopped /dev/md0

注意：停止磁盘阵列前要从文件系统umount磁盘阵列；停止后，原组成阵列的磁盘将处于空闲状态，一旦误操作这些磁盘，将不能再 重启激活原阵列。

6-4、启动磁盘阵列（--assemble）

[root@localhost ~]# mdadm -A /dev/md0 /dev/sd{b,c,d}1

mdadm: /dev/md0 has been started with 3 drives.

因为上面配置了/etc/mdadm.conf文件，也可以用-s查找

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

mdadm: stopped /dev/md0

[root@localhost ~]# mdadm -As /dev/md0

mdadm: /dev/md0 has been started with 3 drives.

6-5、检查磁盘属于哪个阵列（--examine）

[root@localhost ~]# mdadm -E /dev/sdb1

/dev/sdb1:

Magic : a92b4efc

Version : 0.90.00

UUID : 75e92985:cb128e1d:a99bce53:46f65900

Creation Time : Sat Aug 21 23:11:22 2010

Raid Level : raid0

Used Dev Size : 0

Raid Devices : 3

Total Devices : 3

Preferred Minor : 0

Update Time : Sat Aug 21 23:11:22 2010

State : active

Active Devices : 3

Working Devices : 3

Failed Devices : 0

Spare Devices : 0

Checksum : 739a0841 - correct

Events : 1

Chunk Size : 64K

Number   Major   Minor   RaidDevice State

this     0       8       17        0      active sync   /dev/sdb1

0     0       8       17        0      active sync   /dev/sdb1

1     1       8       33        1      active sync   /dev/sdc1

2     2       8       49        2      active sync   /dev/sdd1

6-6、删除和添加磁盘：mdadm可以在Manage模式下，对运行中的阵列进行删除和添加磁盘。常用于标识failed磁盘，增加spare（冗余）磁盘，以及替换磁盘等。

6-6-1、删除磁盘阵列

6-6-1a、查看目前磁盘状态

[root@localhost ~]# mdadm -D /dev/md0

/dev/md0:

Version : 0.90

Creation Time : Sat Aug 21 23:11:22 2010

Raid Level : raid0

Array Size : 3132288 (2.99 GiB 3.21 GB)

Raid Devices : 3

Total Devices : 3

Preferred Minor : 0

Persistence : Superblock is persistent

Update Time : Sat Aug 21 23:11:22 2010

State : clean

Active Devices : 3

Working Devices : 3

Failed Devices : 0

Spare Devices : 0

Chunk Size : 64K

UUID : 75e92985:cb128e1d:a99bce53:46f65900

Events : 0.1

Number   Major   Minor   RaidDevice State

0       8       17        0      active sync   /dev/sdb1

1       8       33        1      active sync   /dev/sdc1

2       8       49        2      active sync   /dev/sdd1

6-6-1b、删除磁盘阵列

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

mdadm: stopped /dev/md0

6-6-1c、修改/etc/mdadm.conf、/ect/fstab等配置文件的/dev/md0相关参数的地方去掉

6-6-2、创建新的磁盘阵列RAID1

[root@localhost ~]# mdadm -Cv /dev/md1 -l1 -n3 /dev/sd{b,c,d}1

mdadm: /dev/sdb1 appears to contain an ext2fs file system

size=3132288K  mtime=Sat Aug 21 23:35:25 2010

mdadm: /dev/sdb1 appears to be part of a raid array:

level=raid0 devices=3 ctime=Sat Aug 21 23:11:22 2010

mdadm: /dev/sdc1 appears to be part of a raid array:

level=raid0 devices=3 ctime=Sat Aug 21 23:11:22 2010

mdadm: /dev/sdd1 appears to be part of a raid array:

level=raid0 devices=3 ctime=Sat Aug 21 23:11:22 2010

mdadm: size set to 1044096K

Continue creating array? y

mdadm: array /dev/md1 started.

查看磁盘阵列状态

[root@localhost ~]# cat /proc/mdstat

Personalities : [raid0] [raid1]

md1 : active raid1 sdd1[2] sdc1[1] sdb1[0]

1044096 blocks [3/3] [UUU]

unused devices: <none>

配置 /etc/mdadm.conf文件：

[root@localhost ~]# echo DEVICE /dev/sd{b,c,d}1 >> /etc/mdadm.conf

[root@localhost ~]# mdadm --detail --scan >> /etc/mdadm.conf

查看磁盘阵列的详细信息

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

/dev/md1:

Version : 0.90

Creation Time : Sun Aug 22 16:53:39 2010

Raid Level : raid1

Array Size : 1044096 (1019.80 MiB 1069.15 MB)

Used Dev Size : 1044096 (1019.80 MiB 1069.15 MB)

Raid Devices : 3

Total Devices : 3

Preferred Minor : 1

Persistence : Superblock is persistent

Update Time : Sun Aug 22 16:53:57 2010

State : clean

Active Devices : 3

Working Devices : 3

Failed Devices : 0

Spare Devices : 0

UUID : e8030aeb:b0324799:98ea885e:c1e1b507

Events : 0.2

Number   Major   Minor   RaidDevice State

0       8       17        0      active sync   /dev/sdb1

1       8       33        1      active sync   /dev/sdc1

2       8       49        2      active sync   /dev/sdd1

6-6-3、移除磁盘：可以使用--fail参数指定坏磁盘，并移除该磁盘（--remove）：（某些阵列模式，如raid0，是不能用--fail和--remove的）

[root@localhost ~]# mdadm /dev/md1 --fail /dev/sdc1 --remove /dev/sdc1

mdadm: set /dev/sdc1 faulty in /dev/md1

mdadm: hot removed /dev/sdc1

查看磁盘阵列的信息

[root@localhost ~]# cat /proc/mdstat

Personalities : [raid0] [raid1]

md1 : active raid1 sdd1[2] sdb1[0]

1044096 blocks [3/2] [U_U]

unused devices: <none>

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

/dev/md1:

Version : 0.90

Creation Time : Sun Aug 22 16:53:39 2010

Raid Level : raid1

Array Size : 1044096 (1019.80 MiB 1069.15 MB)

Used Dev Size : 1044096 (1019.80 MiB 1069.15 MB)

Raid Devices : 3

Total Devices : 2

Preferred Minor : 1

Persistence : Superblock is persistent

Update Time : Sun Aug 22 17:01:13 2010

State : clean, degraded

Active Devices : 2

Working Devices : 2

Failed Devices : 0

Spare Devices : 0

UUID : e8030aeb:b0324799:98ea885e:c1e1b507

Events : 0.6

Number   Major   Minor   RaidDevice State

0       8       17        0      active sync   /dev/sdb1

1       0        0        1      removed

2       8       49        2      active sync   /dev/sdd1