centos7配置軟RAID5

時間 2020-12-12

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一、配置環境介紹
操做平臺：VMware workstation
測試環境：centos7 計算機一臺，添加一塊新的硬盤，建立4個分區。模擬4塊新硬盤
二、實踐目的
一、配置RAID5
二、模擬硬盤故障，檢驗RAID5容錯能力，並實現故障盤替換
三、RAID陣列上建立分區
三、建立RAID準備工做
一、首先查看硬盤標籤類型centos

[root@adong ~]# fdisk -l /dev/sdc 
Disk /dev/sdb: 20 GiB, 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
Disklabel type: gpt #爲GPT類型
Disk identifier: 0x25cc0f39

二、由於硬盤標籤類型爲GPT，左移咱們用gdisk命令建立分區便可bash

[root@adong ~]# gdisk /dev/sdc
GPT fdisk (gdisk) version 1.0.3
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): n         #新建分區
Partition number (1-128, default 1):        #默認分區編號便可，默認從1開始
First sector (34-41943006, default = 2048) or {+-}size{KMGTP}:      #指定起始扇區大小，默認便可
Last sector (2048-41943006, default = 41943006) or {+-}size{KMGTP}: +5G     #指定分區大小
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): fd00      #更改分區類型爲LinuxRAID
Changed type of partition to 'Linux RAID'

重複上述步驟，創建4個分區，而後以下操做保存退出ide

Command (? for help): w     #保存分區
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): Y    #上面提示將寫入GPT分區數據，這樣會覆蓋原來的分區，是否繼續
OK; writing new GUID partition table (GPT) to /dev/sdc.
The operation has completed successfully.

此時用於模擬4塊硬盤的分區就建立好了
三、使用mdadm工具建立RAID，陣列的成員能夠使用通配符工具

[root@adong ~]# mdadm --create /dev/md0 --level=5 --raid-devices=3 --spare-device=1 /dev/sdc[1-4]
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

說明：由於作RAID5最少須要3塊磁盤，此前咱們建立了4個分區模擬4個磁盤，因此建立時咱們經過--raid-devices選項指定用於建立raid的磁盤數爲3，而後將剩餘的一個磁盤經過--spare-device選項設置爲備用磁盤。
四、查看RAID配置的詳細信息測試

[root@adong ~]# mdadm --detail /dev/md0 
/dev/md0:
           Version : 1.2
     Creation Time : Sat Dec 12 10:03:04 2020
        Raid Level : raid5
        Array Size : 10475520 (9.99 GiB 10.73 GB)
     Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
      Raid Devices : 3
     Total Devices : 4
       Persistence : Superblock is persistent
       Update Time : Sat Dec 12 10:03:31 2020
             State : clean 
    Active Devices : 3
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 1
            Layout : left-symmetric
        Chunk Size : 512K
Consistency Policy : resync
              Name : adong.com:0  (local to host adong.com)
              UUID : 597cac50:2c13e44b:f5a87d17:c0f2fc8e
            Events : 18
    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       1       8       34        1      active sync   /dev/sdc2
       4       8       35        2      active sync   /dev/sdc3
       3       8       36        -      spare   /dev/sdc4

經過上述信息，咱們能夠看到，有3塊硬盤處於active激活的狀態並sync同步中，一塊硬盤處於spare備用狀態
五、模擬磁盤故障、查看備用盤的工做狀況ui

[root@adong ~]# mdadm /dev/md0 --fail /dev/sdc2
mdadm: set /dev/sdc2 faulty in /dev/md0

經過--fail選項模擬其中一塊磁盤故障centos7

[root@adong ~]# mdadm --detail /dev/md0 
/dev/md0:
           Version : 1.2
     Creation Time : Sat Dec 12 10:03:04 2020
        Raid Level : raid5
        Array Size : 10475520 (9.99 GiB 10.73 GB)
     Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
      Raid Devices : 3
     Total Devices : 4
       Persistence : Superblock is persistent
       Update Time : Sat Dec 12 10:14:34 2020
             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 : 21% complete
              Name : adong.com:0  (local to host adong.com)
              UUID : 597cac50:2c13e44b:f5a87d17:c0f2fc8e
            Events : 23
    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       3       8       36        1      spare rebuilding   /dev/sdc4
       4       8       35        2      active sync   /dev/sdc3
       1       8       34        -      faulty   /dev/sdc2

此時咱們發現原來備用狀態的/dev/sdc4，此時正在進行備用重建，加入到RAID中，替換故障磁盤
六、故障盤修復或者更換新的物理盤，替換原來的問題磁盤
若是是現實物理環境，將新的物理磁盤更換上去便可，此處咱們模擬環境，因此首先要手動移除故障磁盤spa

[root@adong ~]# mdadm /dev/md0 --remove /dev/sdc2
mdadm: hot removed /dev/sdc2 from /dev/md0

而後將新的磁盤添加上去操作系統

[root@adong ~]# mdadm /dev/md0 --add /dev/sdb1
mdadm: added /dev/sdb1

此時咱們查看RAID的信息，發現新添加上的磁盤，處於備用狀態。一切恢復正常code

[root@adong ~]# mdadm --detail /dev/md0 
/dev/md0:
           Version : 1.2
     Creation Time : Sat Dec 12 10:03:04 2020
        Raid Level : raid5
        Array Size : 10475520 (9.99 GiB 10.73 GB)
     Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
      Raid Devices : 3
     Total Devices : 4
       Persistence : Superblock is persistent
       Update Time : Sat Dec 12 10:21:39 2020
             State : clean 
    Active Devices : 3
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 1
            Layout : left-symmetric
        Chunk Size : 512K
Consistency Policy : resync
              Name : adong.com:0  (local to host adong.com)
              UUID : 597cac50:2c13e44b:f5a87d17:c0f2fc8e
            Events : 39
    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       3       8       36        1      active sync   /dev/sdc4
       4       8       35        2      active sync   /dev/sdc3
       5       8       17        -      spare   /dev/sdb1

注意：更換的磁盤大小必定要和現有RAID中的磁盤大小同樣
七、在RAID陣列上建立分區，並格式化文件系統爲xfs
陣列磁盤對操做系統而言，同樣是一個邏輯磁盤，因此咱們能夠像操做單個磁盤同樣對他進行建立分區和格式化文件系統

[root@adong ~]# gdisk /dev/md0 
GPT fdisk (gdisk) version 1.0.3
Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: not present
Creating new GPT entries.
Command (? for help): n         #新建分區
Partition number (1-128, default 1):    #指定分區編號
First sector (34-20951006, default = 2048) or {+-}size{KMGTP}:      #指定起始扇區
Last sector (2048-20951006, default = 20951006) or {+-}size{KMGTP}: +5G     #設置分區大小
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 
Changed type of partition to 'Linux filesystem'
Command (? for help): w     #保存分區
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): Y    #將要寫入GPT分區去數據，原來的分區數據將被覆蓋，是否繼續
OK; writing new GUID partition table (GPT) to /dev/md0.
The operation has completed successfully.

八、查看分區狀況，發現生成一個/dev/mdop1的分區

[root@adong ~]# fdisk -l  /dev/md0
Disk /dev/md0: 10 GiB, 10726932480 bytes, 20951040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 524288 bytes / 1048576 bytes
Disklabel type: gpt
Disk identifier: BD1E493E-652F-4676-AA07-FCC0D601F15C

Device     Start      End  Sectors Size Type
/dev/md0p1  2048 10487807 10485760   5G Linux filesystem

九、針對上述生成的分區記性格式化文件系統xfs

[root@adong ~]# mkfs.xfs /dev/md0p1 
meta-data=/dev/md0p1             isize=512    agcount=8, agsize=163712 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=1309696, imaxpct=25
         =                       sunit=128    swidth=256 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

十、掛載分區到指定目錄/mnt

[root@adong ~]# mount /dev/md0p1 /mnt/

十一、查看磁盤分區使用狀況，能夠看到/dev/mdop1/被掛載到了/mnt/使用空間爲5G

[root@adong ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        383M     0  383M   0% /dev
tmpfs           399M     0  399M   0% /dev/shm
tmpfs           399M   11M  388M   3% /run
tmpfs           399M     0  399M   0% /sys/fs/cgroup
/dev/sda2        23G   12G   11G  53% /
/dev/sda3       6.0G   83M  6.0G   2% /home
/dev/sda1       3.7G  203M  3.3G   6% /boot
tmpfs            80M  4.0K   80M   1% /run/user/0
/dev/md0p1      5.0G   69M  5.0G   2% /mnt

總結：額外經常使用的一些軟RAID操做命令1.中止RAIDmdadm --stop /dev/md0 二、刪除RAID首先中止RAID而後清除RAID陣列中全部磁盤元數據，這樣就完全刪除了，重啓系統也不會被自動安裝mdadm --zero-superblock /dev/sdc1三、監控RAID，若是出現故障，通知管理員nohup mdadm --monitor --mail=root@localhost.com --delay=180 /dev/md0nohup:將監控任務放置後臺運行delay選項：每一個多久對陣列檢查一下