Linux 磁盘管理--RAID5创建

准备

• mdadm
• 三块新硬盘

安装mdadm

• 尝试使用yum install -y mdadm进行安装,可能是我源的问题.竟然报错了

[root@localhost dev]# yum install -y madadm
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
epel/x86_64/metalink                                                                                  |  10 kB  00:00:00
 * base: mirrors.aliyun.com
 * epel: mirrors.aliyun.com
 * extras: mirrors.aliyun.com
 * updates: mirrors.aliyun.com
base                                                                                                  | 3.6 kB  00:00:00
epel                                                                                                  | 4.7 kB  00:00:00
extras                                                                                                | 2.9 kB  00:00:00
updates                                                                                               | 2.9 kB  00:00:00
(1/2): epel/x86_64/updateinfo                                                                         | 1.0 MB  00:00:00
(2/2): epel/x86_64/primary_db                                                                         | 6.8 MB  00:00:03
No package madadm available.
Error: Nothing to do

• 所以只能本地使用rpm包进行安装
  • 挂载镜像

[root@localhost dev]# mount /dev/cdrom /mnt

• 安装mdadm

[root@localhost dev]# rpm -ivh mdadm-3.2.6-31.el7.x86_64.rpm
error: Failed dependencies:
    libreport-filesystem is needed by mdadm-3.2.6-31.el7.x86_64

• 安装libreport-filesystem和mdadm

[root@localhost dev]# rpm -ivh mdadm-3.2.6-31.el7.x86_64.rpm libreport-filesystem-2.1.11-10.el7.centos.x86_64.rpm
Preparing...                         ################################# [100%]
Updating / installing...
  1:libreport-filesystem-2.1.11-10.el################################# [50%]
  2:mdadm-3.2.6-31.el7              ################################# [100%]

创建RAID5

[root@localhost dev]# mdadm -C /dev/md5 -l 5 -n 3 /dev/sd{b,c,d}
mdadm: largest drive (/dev/sdc) exceeds size (8380416K) by more than 1%
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md5 started.

参数

参数	注释
-C	创建RAID
/dev/md5	第一个RAID设备
-l 5	RAID5
-n	RAID成员的数量

格式化并挂载

格式化为xfs

[root@localhost dev]# mkfs.xfs /dev/md5
meta-data=/dev/md5               isize=512    agcount=16, agsize=261760 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=4188160, 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

挂载分区

• 新建md5目录

[root@localhost /]# mkdir md5

• 挂载分区

[root@localhost /]# mount /dev/md5 /md5

验证md5是否可用

• 新建文件

[root@localhost md5]# touch a{1,2,3} && ll
total 0
-rw-r--r-- 1 root root 0 Apr  7 12:39 a1
-rw-r--r-- 1 root root 0 Apr  7 12:39 a2
-rw-r--r-- 1 root root 0 Apr  7 12:39 a3

• 卸载md5

[root@localhost md5]# umount /dev/md5

• 查看md5目录,发现什么都没了

[root@localhost /]# ll /md5
total 0

• 重新挂载md5,文件找回,则md5分区正常

[root@localhost /]# mount /dev/md5 /md5
[root@localhost /]# ll /md5
total 0
-rw-r--r-- 1 root root 0 Apr  7 12:39 a1
-rw-r--r-- 1 root root 0 Apr  7 12:39 a2
-rw-r--r-- 1 root root 0 Apr  7 12:39 a3

查看RAID信息

[root@localhost /]# mdadm -D /dev/md5 //-D查看详细信息
/dev/md5:
        Version : 1.2
  Creation Time : Tue Apr  7 10:54:01 2020
     Raid Level : raid5
     Array Size : 16760832 (15.98 GiB 17.16 GB)
  Used Dev Size : 8380416 (7.99 GiB 8.58 GB)
   Raid Devices : 3
  Total Devices : 3
    Persistence : Superblock is persistent

    Update Time : Tue Apr  7 12:49:32 2020
          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : localhost.localdomain:5  (local to host localhost.localdomain)
           UUID : 92c54122:08d15045:5724004d:5971e4d1
         Events : 18

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       1       8       32        1      active sync   /dev/sdc
       3       8       48        2      active sync   /dev/sdd

模拟一块磁盘损坏

先对分区进行卸载

[root@localhost md5]# umount /dev/md5

模拟磁盘损坏并移除

[root@localhost ~]# mdadm /dev/md5 -f /dev/sdc -r /dev/sdc
mdadm: set /dev/sdc faulty in /dev/md5
mdadm: hot removed /dev/sdc from /dev/md5

查看RAID信息

[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
        Version : 1.2
  Creation Time : Tue Apr  7 10:54:01 2020
     Raid Level : raid5
     Array Size : 16760832 (15.98 GiB 17.16 GB)
  Used Dev Size : 8380416 (7.99 GiB 8.58 GB)
   Raid Devices : 3
  Total Devices : 2
    Persistence : Superblock is persistent

    Update Time : Tue Apr  7 12:56:41 2020
          State : clean, degraded
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : localhost.localdomain:5  (local to host localhost.localdomain)
           UUID : 92c54122:08d15045:5724004d:5971e4d1
         Events : 21

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       -       0        0        1      removed
       3       8       48        2      active sync   /dev/sdd

重新挂载md5,发现数据依然存在

[root@localhost ~]# mount /dev/md5 /md5
[root@localhost ~]# ll /md5
total 0
-rw-r--r-- 1 root root 0 Apr  7 12:39 a1
-rw-r--r-- 1 root root 0 Apr  7 12:39 a2
-rw-r--r-- 1 root root 0 Apr  7 12:39 a3