创建一个 raid 设备
[root@localhost /]# mknod /dev/md1 b 9 1
- mknod 是命令
- /dev/md1 是设备名称,设备名称必须是 md开头后面的 b 代表的是块设备
- 9 是主设备号 ,1是从设备号
- 主设备号不能更改,从设备号系统唯一
创建 raid 5
[root@localhost /]# mdadm -C /dev/md1 -l 5 -n 3 /dev/sdc5 /dev/sdc6 /dev/sdc7
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.
-C代表创建,指定块设备的路径
-l 指定 raid 级别为5
-n 代表硬盘数量
查看
[root@localhost /]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Sat Apr 22 14:55:36 2017
Raid Level : raid5
Array Size : 1021952 (998.00 MiB 1046.48 MB)
Used Dev Size : 510976 (499.00 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Apr 22 14:55:39 2017
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost.localdomain:1 (local to host localhost.localdomain)
UUID : 2a5294bf:dd845f28:c6c3fa2e:ed6d5d20
Events : 18
Number Major Minor RaidDevice State
0 8 37 0 active sync /dev/sdc5
1 8 38 1 active sync /dev/sdc6
3 8 39 2 active sync /dev/sdc7
格式化挂载
[root@localhost /]# mkfs -t xfs /dev/md1
meta-data=/dev/md1 isize=512 agcount=8, agsize=31872 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=254976, imaxpct=25
= sunit=128 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=624, version=2
= sectsz=512 sunit=8 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@localhost /]# mount /dev/md1 /mnt/data
模拟失效
[root@localhost data]# mdadm /dev/md1 -f /dev/sdc7
mdadm: set /dev/sdc7 faulty in /dev/md1
查看
[root@localhost data]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Sat Apr 22 14:55:36 2017
Raid Level : raid5
Array Size : 1021952 (998.00 MiB 1046.48 MB)
Used Dev Size : 510976 (499.00 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Apr 22 15:04:02 2017
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost.localdomain:1 (local to host localhost.localdomain)
UUID : 2a5294bf:dd845f28:c6c3fa2e:ed6d5d20
Events : 22
Number Major Minor RaidDevice State
0 8 37 0 active sync /dev/sdc5
1 8 38 1 active sync /dev/sdc6
- 0 0 2 removed
3 8 39 - faulty /dev/sdc7
移除
[root@localhost data]# mdadm /dev/md1 --remove /dev/sdc7
mdadm: hot removed /dev/sdc7 from /dev/md1
[root@localhost data]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Sat Apr 22 14:55:36 2017
Raid Level : raid5
Array Size : 1021952 (998.00 MiB 1046.48 MB)
Used Dev Size : 510976 (499.00 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Sat Apr 22 15:05:02 2017
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost.localdomain:1 (local to host localhost.localdomain)
UUID : 2a5294bf:dd845f28:c6c3fa2e:ed6d5d20
Events : 27
Number Major Minor RaidDevice State
0 8 37 0 active sync /dev/sdc5
1 8 38 1 active sync /dev/sdc6
- 0 0 2 removed
添加
[root@localhost data]# mdadm /dev/md1 --add /dev/sdc7
mdadm: added /dev/sdc7
[root@localhost data]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Sat Apr 22 14:55:36 2017
Raid Level : raid5
Array Size : 1021952 (998.00 MiB 1046.48 MB)
Used Dev Size : 510976 (499.00 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Apr 22 15:05:52 2017
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : localhost.localdomain:1 (local to host localhost.localdomain)
UUID : 2a5294bf:dd845f28:c6c3fa2e:ed6d5d20
Events : 46
Number Major Minor RaidDevice State
0 8 37 0 active sync /dev/sdc5
1 8 38 1 active sync /dev/sdc6
3 8 39 2 active sync /dev/sdc7