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。

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。

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。

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。

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。

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。

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