在CentOS上创建 Software RAID 10的详解

2020-01-30 15:40:03于海丽

# watch cat /proc/mdstat
Every 2.0s: cat /proc/mdstat                                       Tue Feb 11 12:51:25 2014

Personalities : [raid10]
md0 : active raid10 sdg1[5] sdf1[4] sde1[3] sdd1[2] sdc1[1] sda1[0]
      2197321728 blocks super 1.2 512K chunks 2 near-copies [6/6] [UUUUUU]
      [>....................]  resync =  0.2% (5826816/2197321728) finish=278.9min speed=13
0948K/sec

unused devices: 

等阵列完成初始化后,就可以给 md0 设备创建分区和文件系统了,有了文件系统就可以挂载到系统里:

# fdisk /dev/md0
# mkfs.ext4 /dev/md0p1

# mkdir /raid10
# mount /dev/md0p1 /raid10

修改 /etc/fstab 文件让每次系统启动时自动挂载:

# vi /etc/fstab
...
/dev/md0p1 /raid10 ext4 noatime,rw 0 0

在上面的 /etc/fstab 文件里使用 /dev/md0p1 设备名不是一个好办法,因为 udev 的缘故,这个设备名常在重启系统后变化,所以最好用 UUID,使用 blkid 命令找到相应分区的 UUID:

# blkid
...
/dev/md0p1: UUID="093e0605-1fa2-4279-99b2-746c70b78f1b" TYPE="ext4"

然后修改相应的 fstab,使用 UUID 挂载:

# vi /etc/fstab
...
#/dev/md0p1 /raid10 ext4 noatime,rw 0 0
UUID=093e0605-1fa2-4279-99b2-746c70b78f1b /raid10 ext4 noatime,rw 0 0

查看 RAID 的情况:

# mdadm --query --detail /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Tue Feb 11 12:50:38 2014
     Raid Level : raid10
     Array Size : 2197321728 (2095.53 GiB 2250.06 GB)
  Used Dev Size : 732440576 (698.51 GiB 750.02 GB)
   Raid Devices : 6
  Total Devices : 6
    Persistence : Superblock is persistent

    Update Time : Tue Feb 11 18:48:10 2014
          State : clean
 Active Devices : 6
Working Devices : 6
 Failed Devices : 0
  Spare Devices : 0

         Layout : near=2
     Chunk Size : 512K

           Name : local:0  (local to host local)
           UUID : e3044b6c:5ab972ea:8e742b70:3f766a11
         Events : 70

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       33        1      active sync   /dev/sdc1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1
       4       8       81        4      active sync   /dev/sdf1
       5       8       97        5      active sync   /dev/sdg1