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Linux 常见 RAID 及软 RAID 创建

程序员文章站 2022-06-14 09:46:11
RAID 可以大幅度的提高磁盘性能,以及可靠性,这么好的技术怎么能不掌握呢!此篇介绍一些常见 RAID ,及其在 Linux 上的软 RAID 创建方法。 ......

Linux 常见 RAID 及软 RAID 创建

raid可以大幅度的提高磁盘性能,以及可靠性,这么好的技术怎么能不掌握呢!此篇介绍一些常见raid,及其在linux上的软raid创建方法。


mdadm

  • 创建软raid
mdadm -c -v /dev/创建的设备名 -l级别 -n数量 添加的磁盘 [-x数量 添加的热备份盘]

-c:创建一个新的阵列--create
-v:显示细节--verbose
-l:设定raid级别--level=
-n:指定阵列中可用device数目--raid-devices=
-x:指定初始阵列的富余device数目--spare-devices=,空闲盘(热备磁盘)能在工作盘损坏后自动顶替

  • 查看详细信息
mdadm -d /dev/设备名

-d:打印一个或多个md device的详细信息--detail

  • 查看raid的状态
cat /proc/mdstat
  • 模拟损坏
mdadm -f /dev/设备名 磁盘

-f:模拟损坏fail

  • 移除损坏
mdadm -r /dev/设备名 磁盘

-r:移除remove

  • 添加新硬盘作为热备份盘
mdadm -a /dev/设备名 磁盘

-a:添加add


raid0

raid0俗称条带,它将两个或多个硬盘组成一个逻辑硬盘,容量是所有硬盘之和,因为是多个硬盘组合成一个,故可并行写操作,写入速度提高,但此方式硬盘数据没有冗余,没有容错,一旦一个物理硬盘损坏,则所有数据均丢失。因而,raid0适合于对数据量大,但安全性要求不高的场景,比如音像、视频文件的存储等。

Linux 常见 RAID 及软 RAID 创建

实验raid0创建,格式化,挂载使用。

1.添加220g的硬盘,分区,类型idfd

[root@localhost ~]# fdisk -l | grep raid
/dev/sdb1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdc1            2048    41943039    20970496   fd  linux raid autodetect

2.创建raid0

[root@localhost ~]# mdadm -c -v /dev/md0 -l0 -n2 /dev/sd{b,c}1
mdadm: chunk size defaults to 512k
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.

3.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid0]
md0 : active raid0 sdc1[1] sdb1[0]
      41906176 blocks super 1.2 512k chunks

unused devices: <none>

4.查看raid0的详细信息。

[root@localhost ~]# mdadm -d /dev/md0
/dev/md0:
           version : 1.2
     creation time : sun aug 25 15:28:13 2019
        raid level : raid0
        array size : 41906176 (39.96 gib 42.91 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 15:28:13 2019
             state : clean
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

        chunk size : 512k

consistency policy : none

              name : localhost:0  (local to host localhost)
              uuid : 7ff54c57:b99a59da:6b56c6d5:a4576ccf
            events : 0

    number   major   minor   raiddevice state
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1

5.格式化。

[root@localhost ~]# mkfs.xfs /dev/md0
meta-data=/dev/md0               isize=512    agcount=16, agsize=654720 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=10475520, imaxpct=25
         =                       sunit=128    swidth=256 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=5120, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

6.挂载使用。

[root@localhost ~]# mkdir /mnt/md0
[root@localhost ~]# mount /dev/md0 /mnt/md0/
[root@localhost ~]# df -ht
filesystem              type      size  used avail use% mounted on
/dev/mapper/centos-root xfs        17g 1013m   16g   6% /
devtmpfs                devtmpfs  901m     0  901m   0% /dev
tmpfs                   tmpfs     912m     0  912m   0% /dev/shm
tmpfs                   tmpfs     912m  8.7m  904m   1% /run
tmpfs                   tmpfs     912m     0  912m   0% /sys/fs/cgroup
/dev/sda1               xfs      1014m  143m  872m  15% /boot
tmpfs                   tmpfs     183m     0  183m   0% /run/user/0
/dev/md0                xfs        40g   33m   40g   1% /mnt/md0

raid1

raid1俗称镜像,它最少由两个硬盘组成,且两个硬盘上存储的数据均相同,以实现数据冗余。raid1读操作速度有所提高,写操作理论上与单硬盘速度一样,但由于数据需要同时写入所有硬盘,实际上稍为下降。容错性是所有组合方式里最好的,只要有一块硬盘正常,则能保持正常工作。但它对硬盘容量的利用率则是最低,只有50%,因而成本也是最高。raid1适合对数据安全性要求非常高的场景,比如存储数据库数据文件之类。

Linux 常见 RAID 及软 RAID 创建

实验raid1创建,格式化,挂载使用,故障模拟,重新添加热备份。

1.添加320g的硬盘,分区,类型idfd

[root@localhost ~]# fdisk -l | grep raid
/dev/sdb1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdc1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdd1            2048    41943039    20970496   fd  linux raid autodetect

2.创建raid1,并添加1个热备份盘。

[root@localhost ~]# mdadm -c -v /dev/md1 -l1 -n2 /dev/sd{b,c}1 -x1 /dev/sdd1
mdadm: note: this array has metadata at the start and
    may not be suitable as a boot device.  if you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: size set to 20953088k
continue creating array? y
mdadm: fail create md1 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.

3.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md1 : active raid1 sdd1[2](s) sdc1[1] sdb1[0]
      20953088 blocks super 1.2 [2/2] [uu]
      [========>............]  resync = 44.6% (9345792/20953088) finish=0.9min speed=203996k/sec

unused devices: <none>
[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md1 : active raid1 sdd1[2](s) sdc1[1] sdb1[0]
      20953088 blocks super 1.2 [2/2] [uu]

unused devices: <none>

4.查看raid1的详细信息。

[root@localhost ~]# mdadm -d /dev/md1
/dev/md1:
           version : 1.2
     creation time : sun aug 25 15:38:44 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 3
       persistence : superblock is persistent

       update time : sun aug 25 15:39:24 2019
             state : clean, resyncing
    active devices : 2
   working devices : 3
    failed devices : 0
     spare devices : 1

consistency policy : resync

     resync status : 40% complete

              name : localhost:1  (local to host localhost)
              uuid : b921e8b3:a18e2fc9:11706ba4:ed633dfd
            events : 6

    number   major   minor   raiddevice state
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1

       2       8       49        -      spare   /dev/sdd1

5.格式化。

[root@localhost ~]# mkfs.xfs /dev/md1
meta-data=/dev/md1               isize=512    agcount=4, agsize=1309568 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=5238272, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

6.挂载使用。

[root@localhost ~]# mkdir /mnt/md1
[root@localhost ~]# mount /dev/md1 /mnt/md1/
[root@localhost ~]# df -ht
filesystem              type      size  used avail use% mounted on
/dev/mapper/centos-root xfs        17g 1014m   16g   6% /
devtmpfs                devtmpfs  901m     0  901m   0% /dev
tmpfs                   tmpfs     912m     0  912m   0% /dev/shm
tmpfs                   tmpfs     912m  8.7m  904m   1% /run
tmpfs                   tmpfs     912m     0  912m   0% /sys/fs/cgroup
/dev/sda1               xfs      1014m  143m  872m  15% /boot
tmpfs                   tmpfs     183m     0  183m   0% /run/user/0
/dev/md1                xfs        20g   33m   20g   1% /mnt/md1

7.创建测试文件。

[root@localhost ~]# touch /mnt/md1/test{1..9}.txt
[root@localhost ~]# ls /mnt/md1/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

8.故障模拟。

[root@localhost ~]# mdadm -f /dev/md1 /dev/sdb1
mdadm: set /dev/sdb1 faulty in /dev/md1

9.查看测试文件。

[root@localhost ~]# ls /mnt/md1/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

10.查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md1 : active raid1 sdd1[2] sdc1[1] sdb1[0](f)
      20953088 blocks super 1.2 [2/1] [_u]
      [=====>...............]  recovery = 26.7% (5600384/20953088) finish=1.2min speed=200013k/sec

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md1
/dev/md1:
           version : 1.2
     creation time : sun aug 25 15:38:44 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 3
       persistence : superblock is persistent

       update time : sun aug 25 15:47:57 2019
             state : active, degraded, recovering
    active devices : 1
   working devices : 2
    failed devices : 1
     spare devices : 1

consistency policy : resync

    rebuild status : 17% complete

              name : localhost:1  (local to host localhost)
              uuid : b921e8b3:a18e2fc9:11706ba4:ed633dfd
            events : 22

    number   major   minor   raiddevice state
       2       8       49        0      spare rebuilding   /dev/sdd1
       1       8       33        1      active sync   /dev/sdc1

       0       8       17        -      faulty   /dev/sdb1

11.再次查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md1 : active raid1 sdd1[2] sdc1[1] sdb1[0](f)
      20953088 blocks super 1.2 [2/2] [uu]

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md1
/dev/md1:
           version : 1.2
     creation time : sun aug 25 15:38:44 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 3
       persistence : superblock is persistent

       update time : sun aug 25 15:49:28 2019
             state : active
    active devices : 2
   working devices : 2
    failed devices : 1
     spare devices : 0

consistency policy : resync

              name : localhost:1  (local to host localhost)
              uuid : b921e8b3:a18e2fc9:11706ba4:ed633dfd
            events : 37

    number   major   minor   raiddevice state
       2       8       49        0      active sync   /dev/sdd1
       1       8       33        1      active sync   /dev/sdc1

       0       8       17        -      faulty   /dev/sdb1

12.移除损坏的磁盘

[root@localhost ~]# mdadm -r /dev/md1 /dev/sdb1
mdadm: hot removed /dev/sdb1 from /dev/md1
[root@localhost ~]# mdadm -d /dev/md1
/dev/md1:
           version : 1.2
     creation time : sun aug 25 15:38:44 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 15:52:57 2019
             state : active
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

consistency policy : resync

              name : localhost:1  (local to host localhost)
              uuid : b921e8b3:a18e2fc9:11706ba4:ed633dfd
            events : 38

    number   major   minor   raiddevice state
       2       8       49        0      active sync   /dev/sdd1
       1       8       33        1      active sync   /dev/sdc1

13.重新添加热备份盘。

[root@localhost ~]# mdadm -a /dev/md1 /dev/sdb1
mdadm: added /dev/sdb1
[root@localhost ~]# mdadm -d /dev/md1
/dev/md1:
           version : 1.2
     creation time : sun aug 25 15:38:44 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 3
       persistence : superblock is persistent

       update time : sun aug 25 15:53:32 2019
             state : active
    active devices : 2
   working devices : 3
    failed devices : 0
     spare devices : 1

consistency policy : resync

              name : localhost:1  (local to host localhost)
              uuid : b921e8b3:a18e2fc9:11706ba4:ed633dfd
            events : 39

    number   major   minor   raiddevice state
       2       8       49        0      active sync   /dev/sdd1
       1       8       33        1      active sync   /dev/sdc1

       3       8       17        -      spare   /dev/sdb1

raid5

raid5最少由三个硬盘组成,它将数据分散存储于阵列中的每个硬盘,并且还伴有一个数据校验位,数据位与校验位通过算法能相互验证,当丢失其中的一位时,raid控制器能通过算法,利用其它两位数据将丢失的数据进行计算还原。因而raid5最多能允许一个硬盘损坏,有容错性。raid5相对于其它的组合方式,在容错与成本方面有一个平衡,因而受到大多数使用者的欢迎。一般的磁盘阵列,最常使用的就是raid5这种方式。

Linux 常见 RAID 及软 RAID 创建

实验raid5创建,格式化,挂载使用,故障模拟,重新添加热备份。

1.添加420g的硬盘,分区,类型idfd

[root@localhost ~]# fdisk -l | grep raid
/dev/sdb1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdc1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdd1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sde1            2048    41943039    20970496   fd  linux raid autodetect

2.创建raid5,并添加1个热备份盘。

[root@localhost ~]# mdadm -c -v /dev/md5 -l5 -n3 /dev/sd[b-d]1 -x1 /dev/sde1
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512k
mdadm: size set to 20953088k
mdadm: fail create md5 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md5 started.

3.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdd1[4] sde1[3](s) sdc1[1] sdb1[0]
      41906176 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [uu_]
      [====>................]  recovery = 24.1% (5057340/20953088) finish=1.3min speed=202293k/sec

unused devices: <none>
[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdd1[4] sde1[3](s) sdc1[1] sdb1[0]
      41906176 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [uuu]

unused devices: <none>

4.查看raid5的详细信息。

[root@localhost ~]# mdadm -d /dev/md5
/dev/md5:
           version : 1.2
     creation time : sun aug 25 16:13:44 2019
        raid level : raid5
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 3
     total devices : 4
       persistence : superblock is persistent

       update time : sun aug 25 16:15:29 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 : localhost:5  (local to host localhost)
              uuid : a055094e:9adaff79:2edae9b9:0dcc3f1b
            events : 18

    number   major   minor   raiddevice state
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
       4       8       49        2      active sync   /dev/sdd1

       3       8       65        -      spare   /dev/sde1

5.格式化。

[root@localhost ~]# mkfs.xfs /dev/md5
meta-data=/dev/md5               isize=512    agcount=16, agsize=654720 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=10475520, imaxpct=25
         =                       sunit=128    swidth=256 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=5120, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

6.挂载使用。

[root@localhost ~]# mkdir /mnt/md5
[root@localhost ~]# mount /dev/md5 /mnt/md5/
[root@localhost ~]# df -ht
filesystem              type      size  used avail use% mounted on
/dev/mapper/centos-root xfs        17g 1014m   16g   6% /
devtmpfs                devtmpfs  901m     0  901m   0% /dev
tmpfs                   tmpfs     912m     0  912m   0% /dev/shm
tmpfs                   tmpfs     912m  8.7m  904m   1% /run
tmpfs                   tmpfs     912m     0  912m   0% /sys/fs/cgroup
/dev/sda1               xfs      1014m  143m  872m  15% /boot
tmpfs                   tmpfs     183m     0  183m   0% /run/user/0
/dev/md5                xfs        40g   33m   40g   1% /mnt/md5

7.创建测试文件。

[root@localhost ~]# touch /mnt/md5/test{1..9}.txt
[root@localhost ~]# ls /mnt/md5/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

8.故障模拟。

[root@localhost ~]# mdadm -f /dev/md5 /dev/sdb1
mdadm: set /dev/sdb1 faulty in /dev/md5

9.查看测试文件。

[root@localhost ~]# ls /mnt/md5/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

10.查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdd1[4] sde1[3] sdc1[1] sdb1[0](f)
      41906176 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [_uu]
      [====>................]  recovery = 21.0% (4411136/20953088) finish=1.3min speed=210054k/sec

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md5
/dev/md5:
           version : 1.2
     creation time : sun aug 25 16:13:44 2019
        raid level : raid5
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 3
     total devices : 4
       persistence : superblock is persistent

       update time : sun aug 25 16:21:31 2019
             state : clean, degraded, recovering
    active devices : 2
   working devices : 3
    failed devices : 1
     spare devices : 1

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

    rebuild status : 12% complete

              name : localhost:5  (local to host localhost)
              uuid : a055094e:9adaff79:2edae9b9:0dcc3f1b
            events : 23

    number   major   minor   raiddevice state
       3       8       65        0      spare rebuilding   /dev/sde1
       1       8       33        1      active sync   /dev/sdc1
       4       8       49        2      active sync   /dev/sdd1

       0       8       17        -      faulty   /dev/sdb1

11.再次查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md5 : active raid5 sdd1[4] sde1[3] sdc1[1] sdb1[0](f)
      41906176 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [uuu]

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md5
/dev/md5:
           version : 1.2
     creation time : sun aug 25 16:13:44 2019
        raid level : raid5
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 3
     total devices : 4
       persistence : superblock is persistent

       update time : sun aug 25 16:23:09 2019
             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:5  (local to host localhost)
              uuid : a055094e:9adaff79:2edae9b9:0dcc3f1b
            events : 39

    number   major   minor   raiddevice state
       3       8       65        0      active sync   /dev/sde1
       1       8       33        1      active sync   /dev/sdc1
       4       8       49        2      active sync   /dev/sdd1

       0       8       17        -      faulty   /dev/sdb1

12.移除损坏的磁盘。

[root@localhost ~]# mdadm -r /dev/md5 /dev/sdb1
mdadm: hot removed /dev/sdb1 from /dev/md5
[root@localhost ~]# mdadm -d /dev/md5
/dev/md5:
           version : 1.2
     creation time : sun aug 25 16:13:44 2019
        raid level : raid5
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 3
     total devices : 3
       persistence : superblock is persistent

       update time : sun aug 25 16:25:01 2019
             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:5  (local to host localhost)
              uuid : a055094e:9adaff79:2edae9b9:0dcc3f1b
            events : 40

    number   major   minor   raiddevice state
       3       8       65        0      active sync   /dev/sde1
       1       8       33        1      active sync   /dev/sdc1
       4       8       49        2      active sync   /dev/sdd1

13.重新添加热备份盘。

[root@localhost ~]# mdadm -a /dev/md5 /dev/sdb1
mdadm: added /dev/sdb1
[root@localhost ~]# mdadm -d /dev/md5
/dev/md5:
           version : 1.2
     creation time : sun aug 25 16:13:44 2019
        raid level : raid5
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 3
     total devices : 4
       persistence : superblock is persistent

       update time : sun aug 25 16:25:22 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 : localhost:5  (local to host localhost)
              uuid : a055094e:9adaff79:2edae9b9:0dcc3f1b
            events : 41

    number   major   minor   raiddevice state
       3       8       65        0      active sync   /dev/sde1
       1       8       33        1      active sync   /dev/sdc1
       4       8       49        2      active sync   /dev/sdd1

       5       8       17        -      spare   /dev/sdb1

raid6

raid6是在raid5的基础上改良而成的,raid6再将数据校验位增加一位,所以允许损坏的硬盘数量也由 raid5的一个增加到二个。由于同一阵列中两个硬盘同时损坏的概率非常少,所以,raid6用增加一块硬盘的代价,换来了比raid5更高的数据安全性。

Linux 常见 RAID 及软 RAID 创建

实验raid6创建,格式化,挂载使用,故障模拟,重新添加热备份。

1.添加620g的硬盘,分区,类型idfd

[root@localhost ~]# fdisk -l | grep raid
/dev/sdb1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdc1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdd1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sde1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdf1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdg1            2048    41943039    20970496   fd  linux raid autodetect

2.创建raid6,并添加2个热备份盘。

[root@localhost ~]# mdadm -c -v /dev/md6 -l6 -n4 /dev/sd[b-e]1 -x2 /dev/sd[f-g]1
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512k
mdadm: size set to 20953088k
mdadm: fail create md6 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md6 started.

3.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md6 : active raid6 sdg1[5](s) sdf1[4](s) sde1[3] sdd1[2] sdc1[1] sdb1[0]
      41906176 blocks super 1.2 level 6, 512k chunk, algorithm 2 [4/4] [uuuu]
      [===>.................]  resync = 18.9% (3962940/20953088) finish=1.3min speed=208575k/sec

unused devices: <none>
[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md6 : active raid6 sdg1[5](s) sdf1[4](s) sde1[3] sdd1[2] sdc1[1] sdb1[0]
      41906176 blocks super 1.2 level 6, 512k chunk, algorithm 2 [4/4] [uuuu]

unused devices: <none>

4.查看raid6的详细信息。

[root@localhost ~]# mdadm -d /dev/md6
/dev/md6:
           version : 1.2
     creation time : sun aug 25 16:34:36 2019
        raid level : raid6
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 4
     total devices : 6
       persistence : superblock is persistent

       update time : sun aug 25 16:34:43 2019
             state : clean, resyncing
    active devices : 4
   working devices : 6
    failed devices : 0
     spare devices : 2

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

     resync status : 10% complete

              name : localhost:6  (local to host localhost)
              uuid : 7c3d15a2:4066f2c6:742f3e4c:82aae1bb
            events : 1

    number   major   minor   raiddevice state
       0       8       17        0      active sync   /dev/sdb1
       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        -      spare   /dev/sdf1
       5       8       97        -      spare   /dev/sdg1

5.格式化。

[root@localhost ~]# mkfs.xfs /dev/md6
meta-data=/dev/md6               isize=512    agcount=16, agsize=654720 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=10475520, imaxpct=25
         =                       sunit=128    swidth=256 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=5120, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

6.挂载使用。

[root@localhost ~]# mkdir /mnt/md6
[root@localhost ~]# mount /dev/md6 /mnt/md6/
[root@localhost ~]# df -ht
filesystem              type      size  used avail use% mounted on
/dev/mapper/centos-root xfs        17g 1014m   16g   6% /
devtmpfs                devtmpfs  901m     0  901m   0% /dev
tmpfs                   tmpfs     912m     0  912m   0% /dev/shm
tmpfs                   tmpfs     912m  8.7m  903m   1% /run
tmpfs                   tmpfs     912m     0  912m   0% /sys/fs/cgroup
/dev/sda1               xfs      1014m  143m  872m  15% /boot
tmpfs                   tmpfs     183m     0  183m   0% /run/user/0
/dev/md6                xfs        40g   33m   40g   1% /mnt/md6

7.创建测试文件。

[root@localhost ~]# touch /mnt/md6/test{1..9}.txt
[root@localhost ~]# ls /mnt/md6/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

8.故障模拟。

[root@localhost ~]# mdadm -f /dev/md6 /dev/sdb1
mdadm: set /dev/sdb1 faulty in /dev/md6
[root@localhost ~]# mdadm -f /dev/md6 /dev/sdc1
mdadm: set /dev/sdc1 faulty in /dev/md6

9.查看测试文件。

[root@localhost ~]# ls /mnt/md6/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

10.查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md6 : active raid6 sdg1[5] sdf1[4] sde1[3] sdd1[2] sdc1[1](f) sdb1[0](f)
      41906176 blocks super 1.2 level 6, 512k chunk, algorithm 2 [4/2] [__uu]
      [====>................]  recovery = 23.8% (4993596/20953088) finish=1.2min speed=208066k/sec

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md6
/dev/md6:
           version : 1.2
     creation time : sun aug 25 16:34:36 2019
        raid level : raid6
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 4
     total devices : 6
       persistence : superblock is persistent

       update time : sun aug 25 16:41:09 2019
             state : clean, degraded, recovering
    active devices : 2
   working devices : 4
    failed devices : 2
     spare devices : 2

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

    rebuild status : 13% complete

              name : localhost:6  (local to host localhost)
              uuid : 7c3d15a2:4066f2c6:742f3e4c:82aae1bb
            events : 27

    number   major   minor   raiddevice state
       5       8       97        0      spare rebuilding   /dev/sdg1
       4       8       81        1      spare rebuilding   /dev/sdf1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1

       0       8       17        -      faulty   /dev/sdb1
       1       8       33        -      faulty   /dev/sdc1

11.再次查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid6] [raid5] [raid4]
md6 : active raid6 sdg1[5] sdf1[4] sde1[3] sdd1[2] sdc1[1](f) sdb1[0](f)
      41906176 blocks super 1.2 level 6, 512k chunk, algorithm 2 [4/4] [uuuu]

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md6
/dev/md6:
           version : 1.2
     creation time : sun aug 25 16:34:36 2019
        raid level : raid6
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 4
     total devices : 6
       persistence : superblock is persistent

       update time : sun aug 25 16:42:42 2019
             state : clean
    active devices : 4
   working devices : 4
    failed devices : 2
     spare devices : 0

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

              name : localhost:6  (local to host localhost)
              uuid : 7c3d15a2:4066f2c6:742f3e4c:82aae1bb
            events : 46

    number   major   minor   raiddevice state
       5       8       97        0      active sync   /dev/sdg1
       4       8       81        1      active sync   /dev/sdf1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1

       0       8       17        -      faulty   /dev/sdb1
       1       8       33        -      faulty   /dev/sdc1

12.移除损坏的磁盘。

[root@localhost ~]# mdadm -r /dev/md6 /dev/sd{b,c}1
mdadm: hot removed /dev/sdb1 from /dev/md6
mdadm: hot removed /dev/sdc1 from /dev/md6
[root@localhost ~]# mdadm -d /dev/md6
/dev/md6:
           version : 1.2
     creation time : sun aug 25 16:34:36 2019
        raid level : raid6
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 4
     total devices : 4
       persistence : superblock is persistent

       update time : sun aug 25 16:43:43 2019
             state : clean
    active devices : 4
   working devices : 4
    failed devices : 0
     spare devices : 0

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

              name : localhost:6  (local to host localhost)
              uuid : 7c3d15a2:4066f2c6:742f3e4c:82aae1bb
            events : 47

    number   major   minor   raiddevice state
       5       8       97        0      active sync   /dev/sdg1
       4       8       81        1      active sync   /dev/sdf1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1

13.重新添加热备份盘。

[root@localhost ~]# mdadm -a /dev/md6 /dev/sd{b,c}1
mdadm: added /dev/sdb1
mdadm: added /dev/sdc1
[root@localhost ~]# mdadm -d /dev/md6
/dev/md6:
           version : 1.2
     creation time : sun aug 25 16:34:36 2019
        raid level : raid6
        array size : 41906176 (39.96 gib 42.91 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 4
     total devices : 6
       persistence : superblock is persistent

       update time : sun aug 25 16:44:01 2019
             state : clean
    active devices : 4
   working devices : 6
    failed devices : 0
     spare devices : 2

            layout : left-symmetric
        chunk size : 512k

consistency policy : resync

              name : localhost:6  (local to host localhost)
              uuid : 7c3d15a2:4066f2c6:742f3e4c:82aae1bb
            events : 49

    number   major   minor   raiddevice state
       5       8       97        0      active sync   /dev/sdg1
       4       8       81        1      active sync   /dev/sdf1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1

       6       8       17        -      spare   /dev/sdb1
       7       8       33        -      spare   /dev/sdc1

raid10

raid10是先将数据进行镜像操作,然后再对数据进行分组,raid1在这里就是一个冗余的备份阵列,而raid0则负责数据的读写阵列。至少要四块盘,两两组合做raid1,然后做raid0raid10对存储容量的利用率和raid1一样低,只有50%raid10方案造成了50%的磁盘浪费,但是它提供了200%的速度和单磁盘损坏的数据安全性,并且当同时损坏的磁盘不在同一raid1中,就能保证数据安全性,raid10能提供比raid5更好的性能。这种新结构的可扩充性不好,使用此方案比较昂贵。

Linux 常见 RAID 及软 RAID 创建

实验raid10创建,格式化,挂载使用,故障模拟,重新添加热备份。

1.添加420g的硬盘,分区,类型idfd

[root@localhost ~]# fdisk -l | grep raid
/dev/sdb1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdc1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sdd1            2048    41943039    20970496   fd  linux raid autodetect
/dev/sde1            2048    41943039    20970496   fd  linux raid autodetect

2.创建两个raid1,不添加热备份盘。

[root@localhost ~]# mdadm -c -v /dev/md101 -l1 -n2 /dev/sd{b,c}1
mdadm: note: this array has metadata at the start and
    may not be suitable as a boot device.  if you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: size set to 20953088k
continue creating array? y
mdadm: fail create md101 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md101 started.
[root@localhost ~]# mdadm -c -v /dev/md102 -l1 -n2 /dev/sd{d,e}1
mdadm: note: this array has metadata at the start and
    may not be suitable as a boot device.  if you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: size set to 20953088k
continue creating array? y
mdadm: fail create md102 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md102 started.

3.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md102 : active raid1 sde1[1] sdd1[0]
      20953088 blocks super 1.2 [2/2] [uu]
      [=========>...........]  resync = 48.4% (10148224/20953088) finish=0.8min speed=200056k/sec

md101 : active raid1 sdc1[1] sdb1[0]
      20953088 blocks super 1.2 [2/2] [uu]
      [=============>.......]  resync = 69.6% (14604672/20953088) finish=0.5min speed=200052k/sec

unused devices: <none>
[root@localhost ~]# cat /proc/mdstat
personalities : [raid1]
md102 : active raid1 sde1[1] sdd1[0]
      20953088 blocks super 1.2 [2/2] [uu]

md101 : active raid1 sdc1[1] sdb1[0]
      20953088 blocks super 1.2 [2/2] [uu]

unused devices: <none>

4.查看两个raid1的详细信息。

[root@localhost ~]# mdadm -d /dev/md101
/dev/md101:
           version : 1.2
     creation time : sun aug 25 16:53:00 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 16:53:58 2019
             state : clean, resyncing
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

consistency policy : resync

     resync status : 62% complete

              name : localhost:101  (local to host localhost)
              uuid : 80bb4fc5:1a628936:275ba828:17f23330
            events : 9

    number   major   minor   raiddevice state
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
[root@localhost ~]# mdadm -d /dev/md102
/dev/md102:
           version : 1.2
     creation time : sun aug 25 16:53:23 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 16:54:02 2019
             state : clean, resyncing
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

consistency policy : resync

     resync status : 42% complete

              name : localhost:102  (local to host localhost)
              uuid : 38abac72:74fa8a53:3a21b5e4:01ae64cd
            events : 6

    number   major   minor   raiddevice state
       0       8       49        0      active sync   /dev/sdd1
       1       8       65        1      active sync   /dev/sde1

5.创建raid10

[root@localhost ~]# mdadm -c -v /dev/md10 -l0 -n2 /dev/md10{1,2}
mdadm: chunk size defaults to 512k
mdadm: fail create md10 when using /sys/module/md_mod/parameters/new_array
mdadm: defaulting to version 1.2 metadata
mdadm: array /dev/md10 started.

6.查看raidstat状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1] [raid0]
md10 : active raid0 md102[1] md101[0]
      41871360 blocks super 1.2 512k chunks

md102 : active raid1 sde1[1] sdd1[0]
      20953088 blocks super 1.2 [2/2] [uu]

md101 : active raid1 sdc1[1] sdb1[0]
      20953088 blocks super 1.2 [2/2] [uu]

unused devices: <none>

7.查看raid10的详细信息。

[root@localhost ~]# mdadm -d /dev/md10
/dev/md10:
           version : 1.2
     creation time : sun aug 25 16:56:08 2019
        raid level : raid0
        array size : 41871360 (39.93 gib 42.88 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 16:56:08 2019
             state : clean
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

        chunk size : 512k

consistency policy : none

              name : localhost:10  (local to host localhost)
              uuid : 23c6abac:b131a049:db25cac8:686fb045
            events : 0

    number   major   minor   raiddevice state
       0       9      101        0      active sync   /dev/md101
       1       9      102        1      active sync   /dev/md102

8.格式化。

[root@localhost ~]# mkfs.xfs /dev/md10
meta-data=/dev/md10              isize=512    agcount=16, agsize=654208 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=10467328, imaxpct=25
         =                       sunit=128    swidth=256 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=5112, version=2
         =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

9.挂载使用。

[root@localhost ~]# mkdir /mnt/md10
[root@localhost ~]# mount /dev/md10 /mnt/md10/
[root@localhost ~]# df -ht
filesystem              type      size  used avail use% mounted on
/dev/mapper/centos-root xfs        17g 1014m   16g   6% /
devtmpfs                devtmpfs  901m     0  901m   0% /dev
tmpfs                   tmpfs     912m     0  912m   0% /dev/shm
tmpfs                   tmpfs     912m  8.7m  903m   1% /run
tmpfs                   tmpfs     912m     0  912m   0% /sys/fs/cgroup
/dev/sda1               xfs      1014m  143m  872m  15% /boot
tmpfs                   tmpfs     183m     0  183m   0% /run/user/0
/dev/md10               xfs        40g   33m   40g   1% /mnt/md10

10.创建测试文件。

[root@localhost ~]# touch /mnt/md10/test{1..9}.txt
[root@localhost ~]# ls /mnt/md10/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

11.故障模拟。

[root@localhost ~]# mdadm -f /dev/md101 /dev/sdb1
mdadm: set /dev/sdb1 faulty in /dev/md101
[root@localhost ~]# mdadm -f /dev/md102 /dev/sdd1
mdadm: set /dev/sdd1 faulty in /dev/md102

12.查看测试文件。

[root@localhost ~]# ls /mnt/md10/
test1.txt  test2.txt  test3.txt  test4.txt  test5.txt  test6.txt  test7.txt  test8.txt  test9.txt

13.查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1] [raid0]
md10 : active raid0 md102[1] md101[0]
      41871360 blocks super 1.2 512k chunks

md102 : active raid1 sde1[1] sdd1[0](f)
      20953088 blocks super 1.2 [2/1] [_u]

md101 : active raid1 sdc1[1] sdb1[0](f)
      20953088 blocks super 1.2 [2/1] [_u]

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md101
/dev/md101:
           version : 1.2
     creation time : sun aug 25 16:53:00 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 17:01:11 2019
             state : clean, degraded
    active devices : 1
   working devices : 1
    failed devices : 1
     spare devices : 0

consistency policy : resync

              name : localhost:101  (local to host localhost)
              uuid : 80bb4fc5:1a628936:275ba828:17f23330
            events : 23

    number   major   minor   raiddevice state
       -       0        0        0      removed
       1       8       33        1      active sync   /dev/sdc1

       0       8       17        -      faulty   /dev/sdb1
[root@localhost ~]# mdadm -d /dev/md102
/dev/md102:
           version : 1.2
     creation time : sun aug 25 16:53:23 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 17:00:43 2019
             state : clean, degraded
    active devices : 1
   working devices : 1
    failed devices : 1
     spare devices : 0

consistency policy : resync

              name : localhost:102  (local to host localhost)
              uuid : 38abac72:74fa8a53:3a21b5e4:01ae64cd
            events : 19

    number   major   minor   raiddevice state
       -       0        0        0      removed
       1       8       65        1      active sync   /dev/sde1

       0       8       49        -      faulty   /dev/sdd1
[root@localhost ~]# mdadm -d /dev/md10
/dev/md10:
           version : 1.2
     creation time : sun aug 25 16:56:08 2019
        raid level : raid0
        array size : 41871360 (39.93 gib 42.88 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 16:56:08 2019
             state : clean
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

        chunk size : 512k

consistency policy : none

              name : localhost:10  (local to host localhost)
              uuid : 23c6abac:b131a049:db25cac8:686fb045
            events : 0

    number   major   minor   raiddevice state
       0       9      101        0      active sync   /dev/md101
       1       9      102        1      active sync   /dev/md102

14.移除损坏的磁盘。

[root@localhost ~]# mdadm -r /dev/md101 /dev/sdb1
mdadm: hot removed /dev/sdb1 from /dev/md101
[root@localhost ~]# mdadm -r /dev/md102 /dev/sdd1
mdadm: hot removed /dev/sdd1 from /dev/md102
[root@localhost ~]# mdadm -d /dev/md101
/dev/md101:
           version : 1.2
     creation time : sun aug 25 16:53:00 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 1
       persistence : superblock is persistent

       update time : sun aug 25 17:04:59 2019
             state : clean, degraded
    active devices : 1
   working devices : 1
    failed devices : 0
     spare devices : 0

consistency policy : resync

              name : localhost:101  (local to host localhost)
              uuid : 80bb4fc5:1a628936:275ba828:17f23330
            events : 26

    number   major   minor   raiddevice state
       -       0        0        0      removed
       1       8       33        1      active sync   /dev/sdc1
[root@localhost ~]# mdadm -d /dev/md102
/dev/md102:
           version : 1.2
     creation time : sun aug 25 16:53:23 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 1
       persistence : superblock is persistent

       update time : sun aug 25 17:05:07 2019
             state : clean, degraded
    active devices : 1
   working devices : 1
    failed devices : 0
     spare devices : 0

consistency policy : resync

              name : localhost:102  (local to host localhost)
              uuid : 38abac72:74fa8a53:3a21b5e4:01ae64cd
            events : 20

    number   major   minor   raiddevice state
       -       0        0        0      removed
       1       8       65        1      active sync   /dev/sde1

15.重新添加热备份盘。

[root@localhost ~]# mdadm -a /dev/md101 /dev/sdb1
mdadm: added /dev/sdb1
[root@localhost ~]# mdadm -a /dev/md102 /dev/sdd1
mdadm: added /dev/sdd1

16.再次查看状态。

[root@localhost ~]# cat /proc/mdstat
personalities : [raid1] [raid0]
md10 : active raid0 md102[1] md101[0]
      41871360 blocks super 1.2 512k chunks

md102 : active raid1 sdd1[2] sde1[1]
      20953088 blocks super 1.2 [2/1] [_u]
      [====>................]  recovery = 23.8% (5000704/20953088) finish=1.2min speed=208362k/sec

md101 : active raid1 sdb1[2] sdc1[1]
      20953088 blocks super 1.2 [2/1] [_u]
      [======>..............]  recovery = 32.0% (6712448/20953088) finish=1.1min speed=203407k/sec

unused devices: <none>
[root@localhost ~]# cat /proc/mdstat
personalities : [raid1] [raid0]
md10 : active raid0 md102[1] md101[0]
      41871360 blocks super 1.2 512k chunks

md102 : active raid1 sdd1[2] sde1[1]
      20953088 blocks super 1.2 [2/2] [uu]

md101 : active raid1 sdb1[2] sdc1[1]
      20953088 blocks super 1.2 [2/2] [uu]

unused devices: <none>
[root@localhost ~]# mdadm -d /dev/md101
/dev/md101:
           version : 1.2
     creation time : sun aug 25 16:53:00 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 17:07:28 2019
             state : clean
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

consistency policy : resync

              name : localhost:101  (local to host localhost)
              uuid : 80bb4fc5:1a628936:275ba828:17f23330
            events : 45

    number   major   minor   raiddevice state
       2       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
[root@localhost ~]# mdadm -d /dev/md102
/dev/md102:
           version : 1.2
     creation time : sun aug 25 16:53:23 2019
        raid level : raid1
        array size : 20953088 (19.98 gib 21.46 gb)
     used dev size : 20953088 (19.98 gib 21.46 gb)
      raid devices : 2
     total devices : 2
       persistence : superblock is persistent

       update time : sun aug 25 17:07:36 2019
             state : clean
    active devices : 2
   working devices : 2
    failed devices : 0
     spare devices : 0

consistency policy : resync

              name : localhost:102  (local to host localhost)
              uuid : 38abac72:74fa8a53:3a21b5e4:01ae64cd
            events : 39

    number   major   minor   raiddevice state
       2       8       49        0      active sync   /dev/sdd1
       1       8       65        1      active sync   /dev/sde1

常用 raid 间比较

名称 硬盘数量 容量/利用率 读性能 写性能 数据冗余
raid0 n n块总和 n倍 n倍 无,一个故障,丢失所有数据
raid1 n(偶数) 50% 写两个设备,允许一个故障
raid5 n≥3 (n-1)/n ↑↑ 计算校验,允许一个故障
raid6 n≥4 (n-2)/n ↑↑ ↓↓ 双重校验,允许两个故障
raid10 n(偶数,n≥4) 50% (n/2)倍 (n/2)倍 允许基组中的磁盘各损坏一个

一些话

此篇涉及到的操作很简单,但是,有很多的查看占用了大量的篇幅,看关键点,过程都是一个套路,都是重复的。