linux RAID10测试

mdadm命令用于管理系统软件RAID硬盘阵列，格式为："mdadm [模式] <RAID设备名称> [选项] [成员设备名称]"。

mdadm命令能够在Linux系统中创建和管理软件RAID磁盘阵列组，对于其中的理论知识和操作过程是与生产环境保持一致的~mdadm命令的常用参数包括有：

参数	作用
-a	检测设备名称
-n	指定设备数量
-l	指定raid级别
-C	创建
-v	显示过程
-f	模拟设备损坏
-r	移除设备
-Q	查看摘要信息
-D	查看详细信息
-S	停止阵列

一、创建平盘阵列并挂载使用

第1步：使用mdadm命令创建RAID10,名称为"/dev/md0"。

[root@victory dev]# mdadm -Cv /dev/md0 -a yes -n 4 -l 10 /dev/sdb /dev/sdc /dev/sdd /dev/sde
mdadm: layout defaults to n2
mdadm: layout defaults to n2
mdadm: chunk size defaults to 512K
mdadm: size set to 5238784K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

第2步：把制作好的RAID磁盘阵列组格式化为xfs格式：

[root@victory dev]# mkfs.xfs /dev/md0
meta-data=/dev/md0               isize=    agcount=, agsize= blks
         =                       sectsz=   attr=, projid32bit=
         =                       crc=        finobt=
data     =                       bsize=   blocks=, imaxpct=
         =                       sunit=    swidth= blks
naming   =version               bsize=   ascii-ci= ftype=
log      =internal log           bsize=   blocks=, version=
         =                       sectsz=   sunit= blks, lazy-count=
realtime =none                   extsz=   blocks=, rtextents=
[root@victory dev]# fdisk -l

Disk /dev/sdd:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/sdb:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/sdc:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/sda:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk label type: dos
Disk identifier: 0x0006ae1e

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *                         Linux
/dev/sda2                      8e  Linux LVM

Disk /dev/sde:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/mapper/rhel-root:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/mapper/rhel-swap:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

Disk /dev/md0: 10.7 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

第3步：创建挂载点然后把存储设备进行挂载操作，挂载成功后可看到可用空间为10G：

[root@victory dev]# mkdir /fuckRAID
[root@victory dev]# mount /dev/md0 /fuckRAID/
[root@victory dev]# df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root  .7G  896M  .9G  % /
devtmpfs               910M       910M   % /dev
tmpfs                  920M       920M   % /dev/shm
tmpfs                  920M  8.4M  912M   % /run
tmpfs                  920M       920M   % /sys/fs/cgroup
/dev/sda1              297M  114M  184M  % /boot
tmpfs                  184M       184M   % /run/user/
/dev/md0                10G   33M   10G   % /fuckRAID

第4步：查看/dev/md0磁盘阵列设备组详细信息，并把挂载信息写入到配置文件中永久生效：

[root@victory dev]# mdadm -D /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Tue Aug   ::
     Raid Level : raid10
     Array Size :  (9.99 GiB 10.73 GB)
  Used Dev Size :  (5.00 GiB 5.36 GB)
   Raid Devices :
  Total Devices :
    Persistence : Superblock is persistent

    Update Time : Tue Aug   ::
          State : clean
 Active Devices :
Working Devices :
 Failed Devices :
  Spare Devices : 

         Layout : near=
     Chunk Size : 512K

           Name : victory.rusky.com:  (local to host victory.rusky.com)
           UUID : 6829f476:39a119d4:93da652e:83e096e3
         Events : 

    Number   Major   Minor   RaidDevice State
                                   active sync set-A   /dev/sdb
                                   active sync set-B   /dev/sdc
                                   active sync set-A   /dev/sdd
                                   active sync set-B   /dev/sde
[root@victory dev]# vi /etc/fstab 

#
# /etc/fstab
# Created by anaconda on Tue Aug   ::
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(), findfs(), mount() and/or blkid() for more info
#
/dev/mapper/rhel-root   /                       xfs     defaults
UUID=e7987771-c54c-4b36-8a5c-8e71f129c3fe /boot                   xfs     defaults
/dev/mapper/rhel-swap   swap                    swap    defaults
/dev/md0                /fuckRAID               xfs     defaults         

二、模拟损坏磁盘阵列及修复

[root@victory dev]# mdadm /dev/md0 -f /dev/sdb
mdadm: set /dev/sdb faulty in /dev/md0
[root@victory dev]# mdadm -D /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Tue Aug   ::
     Raid Level : raid10
     Array Size :  (9.99 GiB 10.73 GB)
  Used Dev Size :  (5.00 GiB 5.36 GB)
   Raid Devices :
  Total Devices :
    Persistence : Superblock is persistent

    Update Time : Tue Aug   ::
          State : clean, degraded
 Active Devices :
Working Devices :
 Failed Devices :
  Spare Devices : 

         Layout : near=
     Chunk Size : 512K

           Name : victory.rusky.com:  (local to host victory.rusky.com)
           UUID : 6829f476:39a119d4:93da652e:83e096e3
         Events : 

    Number   Major   Minor   RaidDevice State
                                    removed
                                   active sync set-B   /dev/sdc
                                   active sync set-A   /dev/sdd
                                   active sync set-B   /dev/sde

                             -      faulty   /dev/sdb
[root@victory dev]# 

[root@victory ~]# umount /fuckRAID/
[root@victory ~]# df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root  3.7G  896M  2.9G  24% /
devtmpfs               910M     0  910M   0% /dev
tmpfs                  920M     0  920M   0% /dev/shm
tmpfs                  920M  8.4M  912M   1% /run
tmpfs                  920M     0  920M   0% /sys/fs/cgroup
/dev/sda1              297M  129M  168M  44% /boot
tmpfs                  184M     0  184M   0% /run/user/0
[root@victory ~]# mdadm /dev/md0 -a /dev/sdb
mdadm: added /dev/sdb
[root@victory ~]# mdadm -D /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Tue Aug  1 21:59:41 2017
     Raid Level : raid10
     Array Size : 10477568 (9.99 GiB 10.73 GB)
  Used Dev Size : 5238784 (5.00 GiB 5.36 GB)
   Raid Devices : 4
  Total Devices : 4
    Persistence : Superblock is persistent

    Update Time : Tue Aug  1 22:35:18 2017
          State : clean, degraded, recovering
 Active Devices : 3
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 1

         Layout : near=2
     Chunk Size : 512K

 Rebuild Status : 80% complete

           Name : victory.rusky.com:0  (local to host victory.rusky.com)
           UUID : 6829f476:39a119d4:93da652e:83e096e3
         Events : 47

    Number   Major   Minor   RaidDevice State
       4       8       16        0      spare rebuilding   /dev/sdb
       1       8       32        1      active sync set-B   /dev/sdc
       2       8       48        2      active sync set-A   /dev/sdd
       3       8       64        3      active sync set-B   /dev/sde
[root@victory ~]# mount -a