[root@RHEL7 ~]# date

Fri Aug 19 21:55:01 CST 2016

准备3个盘

[root@RHEL7 ~]# fdisk /dev/sdb

[root@RHEL7 ~]# fdisk /dev/sdc

[root@RHEL7 ~]# fdisk /dev/sdd

[root@RHEL7 ~]# mdadm -C -v /dev/md5 -l 5 -n 3  /dev/sdb1 /dev/sdc1 /dev/sdd1

mdadm: layout defaults to left-symmetric

mdadm: layout defaults to left-symmetric

mdadm: chunk size defaults to 512K

mdadm: /dev/sdc appears to be part of a raid array:

    level=raid0 devices=0 ctime=Thu Jan  1 08:00:00 1970

mdadm: partition table exists on /dev/sdc but will be lost or

       meaningless after creating array

mdadm: size set to 5237248K

Continue creating array? y

mdadm: Defaulting to version 1.2 metadata

mdadm: array /dev/md5 started.

[root@RHEL7 ~]# mdadm -C -v /dev/md5 -l 5 -n 3 -x 1 /dev/sdb1 /dev/sdc1 /dev/sdd1 

-x 指定热备盘数量

[root@RHEL7 ~]# mdadm -D /dev/md5

/dev/md5:

        Version : 1.2

  Creation Time : Fri Aug 19 21:06:32 2016

     Raid Level : raid5

     Array Size : 10474496 (9.99 GiB 10.73 GB)

  Used Dev Size : 5237248 (4.99 GiB 5.36 GB)

   Raid Devices : 3

  Total Devices : 3

    Persistence : Superblock is persistent

    Update Time : Fri Aug 19 21:06:59 2016

          State : clean

 Active Devices : 3

Working Devices : 3

 Failed Devices : 0

  Spare Devices : 0

         Layout : left-symmetric

     Chunk Size : 512K

           Name : RHEL7.2:5  (local to host RHEL7.2)

           UUID : 34f81bee:05f28fb2:a45ff119:930b98cc

         Events : 18

    Number   Major   Minor   RaidDevice State

       0       8       17        0      active sync   /dev/sdb1

       1       8       32        1      active sync   /dev/sdc1

       3       8       49        2      active sync   /dev/sdd1

创建配置文件

[root@RHEL7 raid5]# mdadm -Dsv

ARRAY /dev/md5 level=raid5 num-devices=3 metadata=1.2 name=RHEL7.2:5 UUID=34f81bee:05f28fb2:a45ff119:930b98cc

   devices=/dev/sdb1,/dev/sdc,/dev/sdd1

[root@RHEL7 raid5]# mdadm -Dsv >> /etc/mdadm.conf

[root@RHEL7 ~]# mkfs -t xfs /dev/md5

log stripe unit (524288 bytes) is too large (maximum is 256KiB)

log stripe unit adjusted to 32KiB

meta-data=/dev/md5               isize=256    agcount=16, agsize=163712 blks

         =                       sectsz=512   attr=2, projid32bit=1

         =                       crc=0

data     =                       bsize=4096   blocks=2618624, imaxpct=25

         =                       sunit=128    swidth=256 blks

naming   =version 2              bsize=4096   ascii-ci=0 ftype=0

log      =internal log           bsize=4096   blocks=2560, version=2

         =                       sectsz=512   sunit=8 blks, lazy-count=1

realtime =none                   extsz=4096   blocks=0, rtextents=0

创建文件系统挂载测试

[root@RHEL7 ~]# mkdir /raid5

[root@RHEL7 ~]# mount /dev/md5 /raid5/

[root@RHEL7 ~]# mount /dev/md5 /raid5/

[root@RHEL7 ~]# cd /raid5/

[root@RHEL7 raid5]# ls

[root@RHEL7 raid5]# dd if=/dev/zero of=aa bs=2M count=200

200+0 records in

200+0 records out

419430400 bytes (419 MB) copied, 4.18005 s, 100 MB/s

[root@RHEL7 raid5]# df /raid5

Filesystem     1K-blocks   Used Available Use% Mounted on

/dev/md5        10464256 442912  10021344   5% /raid5

[root@RHEL7 raid5]# du /raid5

409600    /raid5

开机自动挂载

[root@RHEL7 raid5]# echo "/dev/md5 /raid5 xfs defaults 0 0" >> /etc/fstab

[root@RHEL7 raid5]# tail -1 /etc/fstab

/dev/md5 /raid5 xfs defaults 0 0

清除磁盘信息再添加到RAID里去

[root@RHEL7 ~]# umount /dev/md5

[root@RHEL7 ~]# mdadm -S /dev/md5

mdadm: stopped /dev/md5

[root@RHEL7 ~]# mdadm --zero-superblock /dev/sdb1

[root@RHEL7 ~]# mdadm /dev/md5 --add /dev/sdb1

[root@RHEL7 ~]# mdadm -As

mdadm: /dev/md5 assembled from 1 drive - not enough to start the array.

[root@RHEL7 ~]#删除配置文件后清除RAID

[root@RHEL7 ~]# mdadm -rf /etc/mdadm.conf

RAID10:两种方法,

四块盘直接做RAID10,,第二种先做RAID1,再做RAID0

[root@RHEL7 ~]# mdadm -C -v /dev/md10 -l 10 -n 4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

mdadm: layout defaults to n2

mdadm: layout defaults to n2

mdadm: chunk size defaults to 512K

mdadm: size set to 3142144K

mdadm: Defaulting to version 1.2 metadata

mdadm: array /dev/md10 started.

[root@RHEL7 ~]# cat /dev/md10

^C[root@RHEL7 ~]# cat /proc/mdstat

Personalities : [raid10]

md10 : active raid10 sde1[3] sdd1[2] sdc1[1] sdb1[0]

      6284288 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]

unused devices: <none>