RAID5部署

软RAID与备份盘

1.此处我们还用刚才的4块盘做演示，三块盘做raid，一块盘做备份盘，防止磁盘故障

我们以raid 5 来配置三块磁盘 加上一块备份盘

[root@local-pyyu tmp]# mdadm -Cv /dev/md0 -n 3 -l 5 -x 1 /dev/sdb /dev/sdc /dev/sdd /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: Fail create md0 when using /sys/module/md_mod/parameters/new_array
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

2.检查raid状态

[root@local-pyyu tmp]# mdadm -D /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Fri Dec  6 15:47:46 2019
        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 : Fri Dec  6 15:48:12 2019
             State : clean
    Active Devices : 3
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 1

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : resync

              Name : local-pyyu:0  (local to host local-pyyu)
              UUID : 76645a7d:74bc7aca:6b5c214d:f72ecb0f
            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

格式化磁盘文件系统

[root@local-pyyu tmp]# mkfs.xfs -f /dev/md0
meta-data=/dev/md0               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

挂载文件系统，开始使用分区

[root@local-pyyu tmp]# mount /dev/md0 /chaogeRAID5/

检查挂载情况

[root@local-pyyu tmp]# mount |grep md0
/dev/md0 on /chaogeRAID5 type xfs (rw,relatime,attr2,inode64,sunit=1024,swidth=2048,noquota)

[root@local-pyyu chaogeRAID5]# df -h|grep md0
/dev/md0                  10G   33M   10G    1% /chaogeRAID5

写入数据

[root@local-pyyu chaogeRAID5]# echo {1..10000000} > ceshi.txt
[root@local-pyyu chaogeRAID5]# df -h

见证备份磁盘的作用

1.此时raid中的磁盘情况

[root@local-pyyu chaogeRAID5]# mdadm -D /dev/md0 |grep sd
       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

2.剔除一块磁盘

[root@local-pyyu chaogeRAID5]# mdadm /dev/md0 -f /dev/sdb
mdadm: set /dev/sdb faulty in /dev/md0

3.惊喜的发现，备份磁盘上来了

[root@local-pyyu chaogeRAID5]# mdadm -D /dev/md0 |grep sd
       3       8       64        0      spare rebuilding   /dev/sde
       1       8       32        1      active sync   /dev/sdc
       4       8       48        2      active sync   /dev/sdd
       0       8       16        -      faulty   /dev/sdb

4.磁盘已然可以用