磁盘分区
1. 新建四个磁盘分区，每个大小为5GB，用3个分区来模拟RAID5 ，加一个sde热备份盘
[root@localhost ~]# mdadm -Cv /dev/md5 -l5 -n3 /dev/sdb /dev/sdc /dev/sdd --spare-devices=1 /dev/sde
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512K
mdadm: size set to 5237760K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md5 started.
[root@localhost ~]# 2. 查看RAID的详细信息
[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
Version : 1.2
Creation Time : Thu Apr 14 11:32:29 2022
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Thu Apr 14 11:32:55 2022
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:5 (local to host localhost.localdomain)
UUID : f65449a0:db06de22:7100fdc9:4005464f
Events : 18
Number Major Minor RaidDevice State
0 8 16 0 active sync /dev/sdb
1 8 32 1 active sync /dev/sdc
4 8 48 2 active sync /dev/sdd
3 8 64 - spare /dev/sde
[root@localhost ~]# 3. 模拟磁盘故障
[root@localhost ~]# mdadm -f /dev/md5 /dev/sdb
mdadm: set /dev/sdb faulty in /dev/md5
[root@localhost ~]# 4. 再次查看RAID的详细信息
[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
Version : 1.2
Creation Time : Thu Apr 14 11:32:29 2022
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Thu Apr 14 11:32:55 2022
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:5 (local to host localhost.localdomain)
UUID : f65449a0:db06de22:7100fdc9:4005464f
Events : 18
Number Major Minor RaidDevice State
0 8 16 0 active sync /dev/sdb
1 8 32 1 active sync /dev/sdc
4 8 48 2 active sync /dev/sdd
3 8 64 - spare /dev/sde
[root@localhost ~]# mdadm -f /dev/md5 /dev/sdb
mdadm: set /dev/sdb faulty in /dev/md5
[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
Version : 1.2
Creation Time : Thu Apr 14 11:32:29 2022
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Thu Apr 14 11:35:50 2022
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 1
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:5 (local to host localhost.localdomain)
UUID : f65449a0:db06de22:7100fdc9:4005464f
Events : 37
Number Major Minor RaidDevice State
3 8 64 0 active sync /dev/sde
1 8 32 1 active sync /dev/sdc
4 8 48 2 active sync /dev/sdd
0 8 16 - faulty /dev/sdb
[root@localhost ~]# (查看后发现原来的热备盘正在参与 RAID5 的重建，而原来的/dev/sdb盘变成了坏盘）
5. 热移除故障盘
[root@localhost ~]# mdadm -r /dev/md5 /dev/sdb
mdadm: hot removed /dev/sdb from /dev/md5
[root@localhost ~]# 6. 再次再次查看 RAID 的详细信息
[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
Version : 1.2
Creation Time : Thu Apr 14 11:32:29 2022
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Thu Apr 14 11:40:34 2022
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:5 (local to host localhost.localdomain)
UUID : f65449a0:db06de22:7100fdc9:4005464f
Events : 38
Number Major Minor RaidDevice State
3 8 64 0 active sync /dev/sde
1 8 32 1 active sync /dev/sdc
4 8 48 2 active sync /dev/sdd
[root@localhost ~]# 7. 格式化 RAID 并进行挂载
[root@localhost ~]# mkfs.xfs /dev/md5
meta-data=/dev/md5 isize=512 agcount=16, agsize=163712 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=2618880, imaxpct=25
= sunit=128 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=8 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@localhost ~]# mount /dev/md5 /mnt/
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
devtmpfs 894M 0 894M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 11M 900M 2% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/mapper/centos-root 27G 4.9G 23G 19% /
/dev/sda1 1014M 185M 830M 19% /boot
tmpfs 182M 28K 182M 1% /run/user/0
/dev/sr0 4.4G 4.4G 0 100% /run/media/root/CentOS 7 x86_64
/dev/md5 10G 33M 10G 1% /mnt
[root@localhost ~]# 文章来源地址https://uudwc.com/A/rXLjE
文章来源：https://uudwc.com/A/rXLjE
