Linux软raid创建

    RAID: 

     HBA：基于主机的适配器 

     RAID：Redundent Array of Inexpensive Disks 廉价磁盘阵列

                              Independent       独立磁盘阵列

       Level：仅用于标识磁盘组合方式的不同，不能取代数据备份

          raid0，raid1，raid5，raid10，raid50，jbod

          raid0：提高读写性能，没有容错能力。至少需要两块磁盘 100%

          raid1：至少需要两块硬盘，镜像，硬件容错能力，读性能提升，写性能下降 50%

          raid4：至少需要三块硬盘，允许一块盘出错，读写性能提升，（n-1）/n

          raid5: 至少需要三块硬盘，允许一块盘出错，读写性能提升，（n-1）/n

          raid6: 至少需要四块磁盘，允许两块盘出错。读写性能提升，（n-2）/n

          raid10：至少需要四块磁盘。允许不同组内个各坏一块盘，读写性能提升，50%

          raid01：

          jbod：

        md，可以组合任何块设备

        mdadm，/etc/mdadm.conf

        mdadm:模式化的工具

          -A  Assemble 装配模式

          -C  Create 创建模式

            -n #：用于创建RAID设备的个数

            -x #: 热备磁盘的个数

            -l ：指定RAID级别

            -a ：=yes（自动为创建的RAID设备创建设备文件） md mdp part p 如何创建设备文件

            -c：指定块的大小，默认为512KB

          -F FOLLOW 监控

          -S 停止RAID

          -D --detail: 显示阵列详细信息

          Manage 管理模式专用项

            -f：模拟损害

            -r：模拟移除设备

            -a：模拟添加新设备

        watch 

          -n #:每个#执行一次指定的命令，单位为s

            [root@mail ~]# watch -n1 'cat /proc/mdstat'

     

    使用raid0创建一个6G大小的磁盘。

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      [root@mail ~]# fdisk /dev/sdc
      Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
      Building a new DOS disklabel with disk identifier 0xba68f31c.
      Changes will remain in memory only, until you decide to write them.
      After that, of course, the previous content won't be recoverable.
       
      Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
       
      WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
               switch off the mode (command 'c') and change display units to
               sectors (command 'u').
       
      Command (m for help): n
      Command action
         e   extended
         p   primary partition (1-4)
      p
      Partition number (1-4): 1
      First cylinder (1-2610, default 1):
      Using default value 1
      Last cylinder, +cylinders or +size{K,M,G} (1-2610, default 2610): +6G
       
      Command (m for help): n
      Command action
         e   extended
         p   primary partition (1-4)
      p
      Partition number (1-4): 2
      First cylinder (785-2610, default 785):
      Using default value 785
      Last cylinder, +cylinders or +size{K,M,G} (785-2610, default 2610): +6G
       
      Command (m for help): t
      Partition number (1-4): 1
      Hex code (type L to list codes): fd
      Changed system type of partition 1 to fd (Linux raid autodetect)
       
      Command (m for help): t
      Partition number (1-4): 2
      Hex code (type L to list codes): fd
      Changed system type of partition 2 to 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@mail ~]# mdadm -C /dev/md0 -a yes -l 0 -n 2 /dev/sdc{1,2}
      mdadm: Defaulting to version 1.2 metadata
      mdadm: array /dev/md0 started.
      [root@mail ~]# cat /proc/mdstat
      Personalities : [raid0]
      md0 : active raid0 sdc2[1] sdc1[0]
            12585984 blocks super 1.2 512k chunks
             
      unused devices: <none>
      [root@mail ~]# mdadm -D /dev/md0
      /dev/md0:
              Version : 1.2
        Creation Time : Tue May 10 20:19:43 2016
           Raid Level : raid0
           Array Size : 12585984 (12.00 GiB 12.89 GB)
         Raid Devices : 2
        Total Devices : 2
          Persistence : Superblock is persistent
       
          Update Time : Tue May 10 20:19:43 2016
                State : clean
       Active Devices : 2
      Working Devices : 2
       Failed Devices : 0
        Spare Devices : 0
       
           Chunk Size : 512K
       
                 Name : mail.saviorsyang.com:0  (local to host mail.saviorsyang.com)
                 UUID : b5ec8803:366d2e9d:a1ddd0f2:58101d5c
               Events : 0
       
          Number   Major   Minor   RaidDevice State
             0       8       33        0      active sync   /dev/sdc1
             1       8       34        1      active sync   /dev/sdc2
       
      [root@mail ~]# mke2fs -t ext4 /dev/md0
      mke2fs 1.43-WIP (20-Jun-2013)
      Filesystem label=
      OS type: Linux
      Block size=4096 (log=2)
      Fragment size=4096 (log=2)
      Stride=128 blocks, Stripe width=256 blocks
      786864 inodes, 3146496 blocks
      157324 blocks (5.00%) reserved for the super user
      First data block=0
      Maximum filesystem blocks=3225419776
      97 block groups
      32768 blocks per group, 32768 fragments per group
      8112 inodes per group
      Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208
       
      Allocating group tables: done                           
      Writing inode tables: done                           
      Creating journal (32768 blocks):
      done
      Writing superblocks and filesystem accounting information: done
       
      [root@mail ~]# mkdir  /test/md0
      [root@mail ~]# mount /dev/md0 /test/md0
      [root@mail ~]# mount
      /dev/mapper/vg_demo-lv_root on / type ext4 (rw)
      proc on /proc type proc (rw)
      sysfs on /sys type sysfs (rw)
      devpts on /dev/pts type devpts (rw,gid=5,mode=620)
      tmpfs on /dev/shm type tmpfs (rw)
      /dev/sda1 on /boot type ext4 (rw)
      /dev/sdb1 on /student type ext4 (rw)
      /dev/sr0 on /mnt type iso9660 (ro)
      none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
      /dev/md0 on /test/md0 type ext4 (rw)

      使用raid1创建一个2G大小的磁盘。

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      [root@mail ~]# fdisk /dev/sdc
       
      WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
               switch off the mode (command 'c') and change display units to
               sectors (command 'u').
       
      Command (m for help): n
      Command action
         e   extended
         p   primary partition (1-4)
      e
      Partition number (1-4):
      Value out of range.
      Partition number (1-4): 3
      First cylinder (1569-2610, default 1569):
      Using default value 1569
      Last cylinder, +cylinders or +size{K,M,G} (1569-2610, default 2610):
      Using default value 2610
       
      Command (m for help): n
      Command action
         l   logical (5 or over)
         p   primary partition (1-4)
      l
      First cylinder (1569-2610, default 1569):
      Using default value 1569
      Last cylinder, +cylinders or +size{K,M,G} (1569-2610, default 2610): +2G
       
      Command (m for help): n
      Command action
         l   logical (5 or over)
         p   primary partition (1-4)
      l
      First cylinder (1831-2610, default 1831):
      Using default value 1831
      Last cylinder, +cylinders or +size{K,M,G} (1831-2610, default 2610): +2G
       
      Command (m for help): w
      The partition table has been altered!
       
      Calling ioctl() to re-read partition table.
       
      WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
      The kernel still uses the old table. The new table will be used at
      the next reboot or after you run partprobe(8) or kpartx(8)
      Syncing disks.
       
      [root@mail ~]# fdisk /dev/sdc
       
      WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
               switch off the mode (command 'c') and change display units to
               sectors (command 'u').
       
      Command (m for help): t
      Partition number (1-6): 5
      Hex code (type L to list codes): fd
      Changed system type of partition 5 to fd (Linux raid autodetect)
       
      Command (m for help): t
      Partition number (1-6): 6
      Hex code (type L to list codes): fd
      Changed system type of partition 6 to fd (Linux raid autodetect)
       
      Command (m for help): w
      The partition table has been altered!
       
      Calling ioctl() to re-read partition table.
       
      WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
      The kernel still uses the old table. The new table will be used at
      the next reboot or after you run partprobe(8) or kpartx(8)
      Syncing disks.
           
      [root@mail ~]# partx /dev/sdc
      # 1:        63- 12594959 ( 12594897 sectors,   6448 MB)
      # 2:  12594960- 25189919 ( 12594960 sectors,   6448 MB)
      # 3:  25189920- 41929649 ( 16739730 sectors,   8570 MB)
      # 4:         0-       -1 (        0 sectors,      0 MB)
      # 5:  25189983- 29398949 (  4208967 sectors,   2154 MB)
      # 6:  29399013- 33607979 (  4208967 sectors,   2154 MB)
       
      [root@mail ~]# cat /proc/partitions
      major minor  #blocks  name
       
         8       32   20971520 sdc
         8       33    6297448 sdc1
         8       34    6297480 sdc2
         8       35         31 sdc3
         8       37    2104483 sdc5
         8       38    2104483 sdc6
         8        0   52428800 sda
         8        1     512000 sda1
         8        2   51915776 sda2
         8       16  524288000 sdb
         8       17  524281243 sdb1
         8       48   20971520 sdd
        11        0    3763200 sr0
       252        0   47816704 dm-0
       252        1    4096000 dm-1
         9        0   12585984 md0
      [root@mail ~]# mdadm -C /dev/md1 -a yes -l 1 -n 2 /dev/sdc{5,6}
      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? yes
      mdadm: Defaulting to version 1.2 metadata
      mdadm: array /dev/md1 started.
      [root@mail ~]# cat /proc/mdstat
      Personalities : [raid0] [raid1]
      md1 : active raid1 sdc6[1] sdc5[0]
            2102400 blocks super 1.2 [2/2] [UU]
            [=================>...]  resync = 85.5% (1800064/2102400) finish=0.0min speed=200007K/sec
             
      md0 : active raid0 sdc2[1] sdc1[0]
            12585984 blocks super 1.2 512k chunks
             
      unused devices: <none>
      [root@mail ~]# cat /proc/mdstat
      Personalities : [raid0] [raid1]
      md1 : active raid1 sdc6[1] sdc5[0]
            2102400 blocks super 1.2 [2/2] [UU]
             
      md0 : active raid0 sdc2[1] sdc1[0]
            12585984 blocks super 1.2 512k chunks
             
      unused devices: <none>
       
       
      [root@mail ~]#
      [root@mail ~]# mke2fs -t ext4 /dev/md1
      mke2fs 1.43-WIP (20-Jun-2013)
      Filesystem label=
      OS type: Linux
      Block size=4096 (log=2)
      Fragment size=4096 (log=2)
      Stride=0 blocks, Stripe width=0 blocks
      131648 inodes, 525600 blocks
      26280 blocks (5.00%) reserved for the super user
      First data block=0
      Maximum filesystem blocks=541065216
      17 block groups
      32768 blocks per group, 32768 fragments per group
      7744 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@mail ~]# mkdir -pv /test/md1
      [root@mail ~]# mount /dev/md1 /test/md1
      [root@mail ~]# mount
      /dev/mapper/vg_demo-lv_root on / type ext4 (rw)
      proc on /proc type proc (rw)
      sysfs on /sys type sysfs (rw)
      devpts on /dev/pts type devpts (rw,gid=5,mode=620)
      tmpfs on /dev/shm type tmpfs (rw)
      /dev/sda1 on /boot type ext4 (rw)
      /dev/sdb1 on /student type ext4 (rw)
      /dev/sr0 on /mnt type iso9660 (ro)
      none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
      /dev/md1 on /test/md1 type ext4 (rw)







    posted @ 2016-08-04 21:06  Saviorsyang  阅读(349)  评论(0)    收藏  举报