一、创建物理卷

[root@centos ~]# fdisk /dev/sdb                                 #创建3主分区，每个区5G
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 0x29162724.

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): 1
First sector (2048-41943039, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +5G
Partition 1 of type Linux and of size 5 GiB is set

Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): p
Partition number (2-4, default 2): 2
First sector (10487808-41943039, default 10487808): 
Using default value 10487808
Last sector, +sectors or +size{K,M,G} (10487808-41943039, default 41943039): +5G
Partition 2 of type Linux and of size 5 GiB is set

Command (m for help): n
Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): p
Partition number (3,4, default 3): 3
First sector (20973568-41943039, default 20973568): 
Using default value 20973568
Last sector, +sectors or +size{K,M,G} (20973568-41943039, default 41943039): +5G
Partition 3 of type Linux and of size 5 GiB is set

Command (m for help): t                                                 #修改分区号
Partition number (1-3, default 3): 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): t
Partition number (1-3, default 3): 2
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): t
Partition number (1-3, default 3): 3
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): p                                #查看创建的分区

Disk /dev/sdb: 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: 0x29162724

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    10487807     5242880   8e  Linux LVM
/dev/sdb2        10487808    20973567     5242880   8e  Linux LVM
/dev/sdb3        20973568    31459327     5242880   8e  Linux LVM

Command (m for help): w                       #保存并退出
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

[root@centos ~]# pvcreate /dev/sdb{1,2,3}                   #创建物理卷
  Physical volume "/dev/sdb1" successfully created.
  Physical volume "/dev/sdb2" successfully created.
  Physical volume "/dev/sdb3" successfully created.

[root@centos ~]# pvs                                                     #查看物理卷信息
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda2  centos lvm2 a--  <19.00g    0 
  /dev/sdb1         lvm2 ---    5.00g 5.00g
  /dev/sdb2         lvm2 ---    5.00g 5.00g
  /dev/sdb3         lvm2 ---    5.00g 5.00g

二、创建卷组

[root@centos ~]# vgcreate vg01 /dev/sdb{1,2,3}          #创建卷组 （注：vg01指的是卷组的名称）
  Volume group "vg01" successfully created
[root@centos ~]# vgs                                                      #查看卷组信息
  VG     #PV #LV #SN Attr   VSize   VFree  
  centos   1   2   0 wz--n- <19.00g      0 
  vg01     3   0   0 wz--n- <14.99g <14.99g

三、创建逻辑卷

[root@centos ~]# lvcreate -n lv01 -L +2G vg01           #创建逻辑卷 （注：lv01 是指逻辑卷的名称  -L 后面跟的是逻辑卷的大小）
  Logical volume "lv01" created.
[root@centos ~]# lvs                                                     #查看逻辑卷信息
  LV   VG     Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root centos -wi-ao---- <17.00g                                                    
  swap centos -wi-ao----   2.00g                                                    
  lv01 vg01   -wi-a-----   2.00g        

四、格式化以及挂载

[root@centos ~]# mkdir /lv001                                 #创建文件  
[root@centos ~]# cd /
[root@centos /]# ls
bin  boot  dev  etc  home  lib  lib64  lv001  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

[root@centos /]# cd
[root@centos ~]# ls /dev/vg01                                  #查看逻辑卷
lv01

[root@centos ~]# ll /dev/vg01/lv01                           #其实lv01是dm-2的软链接
lrwxrwxrwx. 1 root root 7 Apr 28 02:38 /dev/vg01/lv01 -> ../dm-2

[root@centos ~]# mkfs.xfs /dev/vg01/lv01              #格式化
meta-data=/dev/vg01/lv01         isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=524288, 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
[root@centos ~]# mount /dev/vg01/lv01 /lv001        #挂载到lv001

[root@centos ~]# df -Th /lv001                                   #查看磁盘大小，解决：删除比较大无用的文件
Filesystem            Type  Size  Used Avail Use% Mounted on
/dev/mapper/vg01-lv01 xfs   2.0G   33M  2.0G   2% /lv001