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    linux磁盤管理軟RAID的實現原理分析和方法分享

    發布日期:2022-04-21 12:50 | 文章來源:CSDN

    1 什么是RAID

    RAID全稱是獨立磁盤冗余陣列(Redundant Array of Independent Disks),基本思想是把多個磁盤組合起來,組合一個磁盤陣列組,使得性能大幅提高。

    RAID分為幾個不同的等級,各個不同的等級均在數據可靠性及讀寫性能做了不同的權衡。實際工作中根據自己的業務需求選擇不同的RAID方案。

    2 RAID的實現方式

    外接式磁盤陣列:通過擴展卡提供適配能力內接式RAID:主板集成RAID控制器安裝OS前在BIOS里配置軟件RAID:通過OS實現

    3 標準的RAID

    3.1 RAID0

    RAID0稱為條帶化存儲,將數據分段存儲在各個磁盤中,讀寫均可以并行處理,因此讀寫速率為單個磁盤的N倍,沒有冗余功能,任何一個磁盤的損壞就會導致的數據不可用。

    3.2 RAID1

    RADI1是鏡像存儲,沒有數據校驗,數據被同等的寫入到2個或者多個磁盤中,寫入速度相對慢, 但是讀取速度比較快。

    3.3 RAID 4

    RADI4在RAID1的基礎上,N個盤用于數據存儲,另外加入了1個磁盤作為校驗盤。一共N+1個盤,任何一個盤壞掉也不影響數據的訪問

    3.4 RAID 5

    RAID5在RAID4的基礎上,由原來的一個盤來存儲校驗數據,改為每個盤都有數據和校驗信息的。

    4 混合RAID

    4.1 RAID01

    先組成RAID0,然后組成RAID1.

    4.2 RAID10

    先組成RAID1,然后組成RAID0

    5 軟RAID的實現

    5.1 RAID5的實現

    創建由三塊硬盤組成的可用空間為2G的RAID5設備,要求其chunk大小為256k,文件系統為ext4,開機可自動掛載至/mydata目錄

    5.1.1 先看看我們的磁盤情況

    [root@centos7 Bash]$ lsblk
    NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    sda 8:0 0 200G 0 disk 
    ├─sda1 8:1 0 1G 0 part /boot
    ├─sda2 8:2 0 128G 0 part 
    ├─sda3 8:3 0 48.8G 0 part /
    ├─sda4 8:4 0 512B 0 part 
    └─sda5 8:5 0 19.5G 0 part /app
    sdb 8:16 0 100G 0 disk 
    sdc 8:32 0 20G 0 disk 
    sdd 8:48 0 20G 0 disk 
    sde 8:64 0 20G 0 disk 
    sdf 8:80 0 20G 0 disk 
    sr0 11:0 1 8.1G 0 rom /run/media/root/CentOS 7 x86_64 

    這里我們使用sdb,sdc,sdd,每個盤創建一個主分區1G,構建RADI5.

    5.1.2 根據實際情況分區

    [root@centos7 Bash]$ fdisk /dev/sdb
    Welcome to fdisk (util-linux 2.23.2).
    Changes will remain in memory only, until you decide to write them.
    Be careful before using the write command.
    Device does not contain a recognized partition table
    Building a new DOS disklabel with disk identifier 0x93d380cf.
    Command (m for help): n
    Partition type:
     p primary (0 primary, 0 extended, 4 free)
     e extended
    Select (default p): p
    Partition number (1-4, default 1): 
    First sector (2048-209715199, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199): +1G
    Partition 1 of type Linux and of size 1 GiB is set
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list all codes): fd
    Changed type of partition 'Linux' to 'Linux raid autodetect'
    Command (m for help): p
    Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk label type: dos
    Disk identifier: 0x93d380cf
     Device Boot Start  End Blocks Id System
    /dev/sdb1  2048 2099199 1048576 fd Linux raid autodetect
    Command (m for help): w
    The partition table has been altered!
    Calling ioctl() to re-read partition table.
    Syncing disks.
    [root@centos7 Bash]$ fdisk /dev/sdc
    Welcome to fdisk (util-linux 2.23.2).
    Changes will remain in memory only, until you decide to write them.
    Be careful before using the write command.
    Device does not contain a recognized partition table
    Building a new DOS disklabel with disk identifier 0xc56b90d8.
    Command (m for help): n
    Partition type:
     p primary (0 primary, 0 extended, 4 free)
     e extended
    Select (default p): p
    Partition number (1-4, default 1): 
    First sector (2048-41943039, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +1G
    Partition 1 of type Linux and of size 1 GiB is set
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list all codes): fd
    Changed type of partition 'Linux' to 'Linux raid autodetect'
    Command (m for help): p
    Disk /dev/sdc: 21.5 GB, 21474836480 bytes, 41943040 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk label type: dos
    Disk identifier: 0xc56b90d8
     Device Boot Start  End Blocks Id System
    /dev/sdc1  2048 2099199 1048576 fd Linux raid autodetect
    Command (m for help): w
    The partition table has been altered!
    Calling ioctl() to re-read partition table.
    Syncing disks.
    [root@centos7 Bash]$ fdisk /dev/sdd
    Welcome to fdisk (util-linux 2.23.2).
    Changes will remain in memory only, until you decide to write them.
    Be careful before using the write command.
    Device does not contain a recognized partition table
    Building a new DOS disklabel with disk identifier 0x7e0900d8.
    Command (m for help): n
    Partition type:
     p primary (0 primary, 0 extended, 4 free)
     e extended
    Select (default p): p
    Partition number (1-4, default 1): 
    First sector (2048-41943039, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +1G
    Partition 1 of type Linux and of size 1 GiB is set
    Command (m for help): p
    Disk /dev/sdd: 21.5 GB, 21474836480 bytes, 41943040 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk label type: dos
    Disk identifier: 0x7e0900d8
     Device Boot Start  End Blocks Id System
    /dev/sdd1  2048 2099199 1048576 83 Linux
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list all codes): fd
    Changed type of partition 'Linux' to 'Linux raid autodetect'
    Command (m for help): w
    The partition table has been altered!
    Calling ioctl() to re-read partition table.
    Syncing disks.

    5.1.3 創建raid

    [root@centos7 Bash]$ mdadm -C /dev/md5 -a yes -l 5 -n 3 /dev/sd{b1,c1,d1} -c 256 # -C指定創建, -a yes 自動創建設備 , -l 設定level , -n 設定磁盤個數, -c chunk大小
    Continue creating array? y
    mdadm: Defaulting to version 1.2 metadata
    mdadm: array /dev/md5 started.
    [root@centos7 Bash]$ mdadm -Ds        # 查看信息
    ARRAY /dev/md5 metadata=1.2 name=centos7.magedu.com:5 UUID=2c8ae60d:a799fcb7:9008a046:ae6ea430
    [root@centos7 Bash]$ mdadm -Ds >/etc/mdadm.conf      # 將軟raid信息寫入到配置文件中去
    [root@centos7 Bash]$ mkdir /mnt/md5 # 創建掛載點目錄 [root@centos7 Bash]$ mkfs.ext4 /dev/md5 # 創建文件系統 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=64 blocks, Stripe width=128 blocks 131072 inodes, 523776 blocks 26188 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=536870912 16 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912 Allocating group tables: done Writing inode tables: done Creating journal (8192 blocks): done Writing superblocks and filesystem accounting information: done [root@centos7 Bash]$ mount /dev/md5 /mnt/md5 # 掛載設備 [root@centos7 Bash]$ tail -n 1 /etc/mtab /dev/md5 /mnt/md5 ext4 rw,seclabel,relatime,stripe=128,data=ordered 0 0 # 查看掛載信息 [root@centos7 Bash]$ tail -n 1 /etc/mtab >>/etc/fstab #添加到fstab文件中,確保開機啟動,這里建議使用uuid

    5.1.4 驗證raid

    [root@centos7 md5]$ mdadm -D /dev/md5       #查看詳細raid5詳細信息,可以發現有3個都是working狀態的
    /dev/md5:
    Version : 1.2
    Creation Time : Wed Dec 6 19:28:22 2017
    Raid Level : raid5
    Array Size : 2095104 (2046.00 MiB 2145.39 MB)
    Used Dev Size : 1047552 (1023.00 MiB 1072.69 MB)
    Raid Devices : 3
    Total Devices : 3
    Persistence : Superblock is persistent
    Update Time : Wed Dec 6 19:39:06 2017
    State : clean 
    Active Devices : 3
    Working Devices : 3
    Failed Devices : 0
    Spare Devices : 0
    Layout : left-symmetric
    Chunk Size : 256K
    Consistency Policy : resync
    Name : centos7.magedu.com:5 (local to host centos7.magedu.com)
    UUID : 2c8ae60d:a799fcb7:9008a046:ae6ea430
    Events : 18
    Number Major Minor RaidDevice State
     0 8 17 0 active sync /dev/sdb1
     1 8 33 1 active sync /dev/sdc1
     3 8 49 2 active sync /dev/sdd1
    [root@centos7 md5]$ man mdadm
    [root@centos7 md5]$ mdadm /dev/md5 -f /dev/sdc1       # -f 設定指定設備故障, 將/dev/sdc1 這個盤標記失敗, 看是否數據能訪問,我這里使用-f標記失敗,工作中可以根據硬盤指示燈判斷磁盤狀態
    mdadm: set /dev/sdc1 faulty in /dev/md5  
    [root@centos7 md5]$ mdadm -D /dev/md5        #在次查看信息,發現工作的是2個, 一個失敗的設備 
    /dev/md5:
    Version : 1.2
    Creation Time : Wed Dec 6 19:28:22 2017
    Raid Level : raid5
    Array Size : 2095104 (2046.00 MiB 2145.39 MB)
    Used Dev Size : 1047552 (1023.00 MiB 1072.69 MB)
    Raid Devices : 3
    Total Devices : 3
    Persistence : Superblock is persistent
    Update Time : Wed Dec 6 19:41:08 2017
    State : clean, degraded        # 這里注意了。 我們的一個盤壞掉了。 raid5狀態為降級使用了。
    Active Devices : 2
    Working Devices : 2
    Failed Devices : 1
    Spare Devices : 0
    Layout : left-symmetric
    Chunk Size : 256K
    Consistency Policy : resync
    Name : centos7.magedu.com:5 (local to host centos7.magedu.com)
    UUID : 2c8ae60d:a799fcb7:9008a046:ae6ea430
    Events : 20
    Number Major Minor RaidDevice State
    0 8 17 0 active sync /dev/sdb1
    - 0 0 1 removed
    3 8 49 2 active sync /dev/sdd1
    1 8 33 - faulty /dev/sdc1
    [root@centos7 md5]$ cat a.txt      # 發現我們的數據還是能訪問的。沒有問題。

    5.1.5 替換設備

    我這里是磁盤壞掉后的執行替換的, 完全可以多一個備用盤, 壞掉自動替換的。

    [root@centos7 md5]$ mdadm /dev/md5 -a /dev/sde1   # 上面我們的sdc1數據損壞,我們需要更換新的磁盤來頂替他的位置。這里添加一個sde1的磁盤, fdisk操作這里省去了。
    mdadm: added /dev/sde1
    [root@centos7 md5]$ mdadm -Ds      # 查看詳細信息
    ARRAY /dev/md5 metadata=1.2 name=centos7.magedu.com:5 UUID=2c8ae60d:a799fcb7:9008a046:ae6ea430
    [root@centos7 md5]$ mdadm -D /dev/md5     # 查看詳細信息
    /dev/md5:
    Version : 1.2
    Creation Time : Wed Dec 6 19:28:22 2017
    Raid Level : raid5
    Array Size : 2095104 (2046.00 MiB 2145.39 MB)
    Used Dev Size : 1047552 (1023.00 MiB 1072.69 MB)
    Raid Devices : 3
    Total Devices : 4
    Persistence : Superblock is persistent
    Update Time : Wed Dec 6 19:50:01 2017
    State : clean       # 狀態恢復正常了。沒有問題
    Active Devices : 3
    Working Devices : 3
    Failed Devices : 1
    Spare Devices : 0
    Layout : left-symmetric
    Chunk Size : 256K
    Consistency Policy : resync
    Name : centos7.magedu.com:5 (local to host centos7.magedu.com)
    UUID : 2c8ae60d:a799fcb7:9008a046:ae6ea430
    Events : 43
    Number Major Minor RaidDevice State
    0 8 17 0 active sync /dev/sdb1
    4 8 65 1 active sync /dev/sde1
    3 8 49 2 active sync /dev/sdd1
    1 8 33 - faulty /dev/sdc1  # 這個盤是壞掉的,我們已經加入了新的磁盤, 這個盤可以干掉了
    [root@centos7 md5]$ man mdadm
    [root@centos7 md5]$ mdadm /dev/md5 --remove /dev/sdc1   # 這個盤我們從raid5中移除去。 
    mdadm: hot removed /dev/sdc1 from /dev/md5

    5.1.6擴展raid

    我們上面使用的是2+1構成的raid5,磁盤利用率為66%,如果我們想改成3+1 可以執行類似如下命令

    [root@centos7 mnt]$ mkadm -G -r /dev/md5 -n 4 -a /dev/sdxx   # 這里我就不測試了。使用/dev/sdxx代替一個設備。-G 是Grown增長的意思,-r 是resizefs的意思,

    5.1.7 清空raid信息

    [root@centos7 mnt]$ umount /dev/md5     # 卸載設備
    [root@centos7 mnt]$ mdadm -S /dev/md5     # 停止raid5 
    mdadm: stopped /dev/md5
    [root@centos7 mnt]$ sed -i '$d' /etc/fstab    # 刪除fstab中關于raid5掛載的行
    [root@centos7 mnt]$ cat /etc/fstab     # 確保fstab沒有大問題
    #
    # /etc/fstab
    # Created by anaconda on Tue Nov 7 16:07:01 2017
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    UUID=59ccea87-3c4e-4bbc-9e2f-3fadb1dcf2e6 /   ext4 defaults 1 1
    UUID=f4e867e8-bcde-43a2-adc7-c80b0948e85f /app   ext4 noatime,usrquota,grpquota 1 2
    UUID=1d6cbe88-ffb4-4adf-bacf-76be1fa75708 /boot   ext4 defaults 1 2
    #UUID=b2c064f5-1ee5-4b5c-9e75-ed41cb99c5aa swap   swap defaults 0 0
    #UUID=a0516c4f-40e6-4919-905a-8b44db12ff7b swap  swap defaults,pri=0 0 0 
    #/dev/sdb2 /test ext4 rw,seclabel,relatime,data=ordered 0 0
    #/dev/sdb1 /home xfs rw,seclabel,relatime,attr2,inode64,usrquota,grpquota 0 0
    [root@centos7 mnt]$ rm -rf /etc/mdadm.conf     # 刪除raid默認配置文件
    [root@centos7 mnt]$ mdadm --zero-superblock /dev/sd{b1,e1,d1,c1}  # 清空設置上的超級塊信息

    5.2 RAID10的實現

    raid10 ,6個分區,2個一組raid1,3組raid0

    5.2.1 案例分析

    分析下,我們創建一個raid10設置,2個設備組成一個raid1,6個設備2個一組可以組成3個raid1, 然后把3個raid1組成一個raid0即可

    5.2.2 先創建6個設備

    [root@centos7 mnt]$ lsblk    # 就是使用fdisk 創建的設備, 具體這里就不寫了。 最終使用lsblk顯示,我們可以看到sdb1,sdb2,sdd1,sde1一共6個磁盤
    NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    sda 8:0 0 200G 0 disk 
    ├─sda1 8:1 0 1G 0 part /boot
    ├─sda2 8:2 0 128G 0 part 
    ├─sda3 8:3 0 48.8G 0 part /
    ├─sda4 8:4 0 512B 0 part 
    └─sda5 8:5 0 19.5G 0 part /app
    sdb 8:16 0 100G 0 disk 
    ├─sdb1 8:17 0 1G 0 part 
    └─sdb2 8:18 0 1G 0 part 
    sdc 8:32 0 20G 0 disk 
    ├─sdc1 8:33 0 1G 0 part 
    └─sdc2 8:34 0 1G 0 part 
    sdd 8:48 0 20G 0 disk 
    └─sdd1 8:49 0 1G 0 part 
    sde 8:64 0 20G 0 disk 
    └─sde1 8:65 0 1G 0 part 
    sdf 8:80 0 20G 0 disk 
    sr0 11:0 1 8.1G 0 rom /run/media/root/CentOS 7 x86_64

    5.2.3 創建raid

    [root@centos7 mnt]$ mdadm -C /dev/md11 -a yes -l 1 -n 2 /dev/sd{b1,c1}    # 創建第一個raid1
    mdadm: /dev/sdb1 appears to be part of a raid array:
     level=raid5 devices=3 ctime=Wed Dec 6 19:28:22 2017
    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: /dev/sdc1 appears to be part of a raid array:
     level=raid5 devices=3 ctime=Wed Dec 6 19:28:22 2017
    Continue creating array? y
    mdadm: Defaulting to version 1.2 metadata
    mdadm: array /dev/md11 started.
    [root@centos7 mnt]$ mdadm -C /dev/md12 -a yes -l 1 -n 2 /dev/sd{b2,c2}    #創建第二個raid1
    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
    Continue creating array? y
    mdadm: Defaulting to version 1.2 metadata
    mdadm: array /dev/md12 started.
    [root@centos7 mnt]$ mdadm -C /dev/md13 -a yes -l 1 -n 2 /dev/sd{d1,e1}     # 創建第三個raid1
    mdadm: /dev/sdd1 appears to be part of a raid array:
    level=raid5 devices=3 ctime=Wed Dec 6 19:28:22 2017
    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: /dev/sde1 appears to be part of a raid array:
    level=raid5 devices=3 ctime=Wed Dec 6 19:28:22 2017
    Continue creating array? y
    mdadm: Defaulting to version 1.2 metadata
    mdadm: array /dev/md13 started.
    [root@centos7 mnt]$ mdadm -C /dev/md10 -a yes -l 0 -n 3 /dev/md{11,12,13}    # 將3個raid1 合并為一個raid0 
    mdadm: /dev/md11 appears to contain an ext2fs file system
    size=2095104K mtime=Wed Dec 6 19:29:45 2017
    mdadm: /dev/md13 appears to contain an ext2fs file system
    size=2095104K mtime=Wed Dec 6 19:29:45 2017
    Continue creating array? y
    mdadm: Defaulting to version 1.2 metadata
    mdadm: array /dev/md10 started.
    [root@centos7 mnt]$ mkfs.ext
    mkfs.ext2 mkfs.ext3 mkfs.ext4  
    [root@centos7 mnt]$ mkfs.ext4 /dev/md10         # 創建文件系統            
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=128 blocks, Stripe width=384 blocks
    196224 inodes, 784896 blocks
    39244 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=805306368
    24 block groups
    32768 blocks per group, 32768 fragments per group
    8176 inodes per group
    Superblock backups stored on blocks: 
    32768, 98304, 163840, 229376, 294912
    Allocating group tables: done    
    Writing inode tables: done    
    Creating journal (16384 blocks): done
    Writing superblocks and filesystem accounting information: done 
    [root@centos7 mnt]$ mdadm -Ds          # 查看配置信息
    ARRAY /dev/md11 metadata=1.2 name=centos7.magedu.com:11 UUID=0ce2cd6c:cd21fab6:3e65cfb5:64bd86f3
    ARRAY /dev/md12 metadata=1.2 name=centos7.magedu.com:12 UUID=8af31dff:efab06ed:48e2613b:a599c774
    ARRAY /dev/md13 metadata=1.2 name=centos7.magedu.com:13 UUID=a8c99d60:2d0c61e7:97a76809:9396c020
    ARRAY /dev/md10 metadata=1.2 name=centos7.magedu.com:10 UUID=50b2fa58:4ce65d67:8c50c853:fa175a28
    [root@centos7 mnt]$ mdadm -Ds >> /etc/mdadm.conf        # 寫配置文件到mdadm的配置文件中
    [root@centos7 mnt]$ mkdir /mnt/md10         # 創建掛載目錄
    [root@centos7 mnt]$ mount /dev/md10 /mnt/md10        # 掛載文件系統
    [root@centos7 mnt]$ tail -n 1 /etc/mtab         # 查看mtab文件中的最后一行, 也就是我們的md10掛載信息
    /dev/md10 /mnt/md10 ext4 rw,seclabel,relatime,stripe=384,data=ordered 0 0
    [root@centos7 mnt]$ tail -n 1 /etc/mtab >> /etc/fstab       #添加到開機啟動

    5.2.4 raid 清除工作

    [root@centos7 mnt]$ umount /dev/md10         # 取消掛載
    [root@centos7 mnt]$ rm -rf /etc/mdadm.conf        # 刪除mdadm的默認配置
    [root@centos7 mnt]$ mdadm -S /dev/md10         # 停止raid0設置
    mdadm: stopped /dev/md10
    [root@centos7 mnt]$ mdadm -S /dev/md11         # 停止raid1設置
    mdadm: stopped /dev/md11
    [root@centos7 mnt]$ mdadm -S /dev/md12         # 停止radi1 設置
    mdadm: stopped /dev/md12 
    [root@centos7 mnt]$ mdadm -S /dev/md13         # 停止raid 1 設置
    mdadm: stopped /dev/md13
    [root@centos7 mnt]$ sed -i '$d' /etc/fstab        # 刪除fstab的掛載 
    [root@centos7 mnt]$ cat /etc/fstab         # 確保正確
    #
    # /etc/fstab
    # Created by anaconda on Tue Nov 7 16:07:01 2017
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    UUID=59ccea87-3c4e-4bbc-9e2f-3fadb1dcf2e6 /   ext4 defaults 1 1
    UUID=f4e867e8-bcde-43a2-adc7-c80b0948e85f /app   ext4 noatime,usrquota,grpquota 1 2
    UUID=1d6cbe88-ffb4-4adf-bacf-76be1fa75708 /boot   ext4 defaults 1 2
    #UUID=b2c064f5-1ee5-4b5c-9e75-ed41cb99c5aa swap   swap defaults 0 0
    #UUID=a0516c4f-40e6-4919-905a-8b44db12ff7b swap  swap defaults,pri=0 0 0 
    #/dev/sdb2 /test ext4 rw,seclabel,relatime,data=ordered 0 0
    #/dev/sdb1 /home xfs rw,seclabel,relatime,attr2,inode64,usrquota,grpquota 0 0
    [root@centos7 mnt]$ mdadm -D           # 再次查看下mdadm信息,確保沒有了
    mdadm: No devices given.
    [root@centos7 mnt]$ mdadm --zero-superblock /dev/sd{b1,b2,c1,c2,d1,e1} # 請求md的元數據信息

    以上就是我們給大家整理的在linux磁盤管理中實現軟RAID的方法講解,大家有不明白的可以在下方的留言區討論。

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