通过扩展Volume Group、Logical Volume来达到扩展文件系统的大小，

我的服务器是建在虚机上的，

分配硬盘空间时，通过修改参数把原来硬盘加大的。

[root@localhost ~]# fdisk -l

Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1044     8281507+  8e  Linux LVM

先创建物理分区

#fdisk /dev/sda

通n键，创建一个主分区；

通t键，输入8e转换为LVM分区 

w键，写入分区表

Disk /dev/sda: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1044     8281507+  8e  Linux LVM
/dev/sda3            1045        3916    23069340   8e  Linux LVM

重启生效，然后创建物理卷(physical volume)

#pvcreate /dev/sda3

  Physical volume "/dev/sda3" successfully created

#pvscan 

查看现有的vg 

#vgdisplay   

  --- Volume group ---
  VG Name               VolGroup00
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               7.88 GB
  PE Size               32.00 MB
  Total PE              252
  Alloc PE / Size       250 / 7.81 GB
  Free  PE / Size       2 / 64.00 MB
  VG UUID               Zv74Nv-kqbn-SpF3-yBcg-brXn-2X0G-5mbJcx

新建vg

#vgcreate vg0 /dev/sda3

通过vgextend命令扩展现有的vg

#vgextend  VolGroup00 /dev/sda3

   Volume group "VolGroup00" successfully extended

#vgdisplay

  --- Volume group ---
  VG Name               VolGroup00
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               29.88 GB
  PE Size               32.00 MB
  Total PE              956
  Alloc PE / Size       250 / 7.81 GB
  Free  PE / Size       706 / 22.06 GB
  VG UUID               Zv74Nv-kqbn-SpF3-yBcg-brXn-2X0G-5mbJcx

#mount

/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
none on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)

可以看到文件系统的 / 是挂载在/dev/mapper/VolGroup00-LogVol00上的，

因此，通过改变lv LogVol00的大小来达到给/增减空间的目的。

# lvscan
  ACTIVE            '/dev/VolGroup00/LogVol00' [5.88 GB] inherit
  ACTIVE            '/dev/VolGroup00/LogVol01' [1.94 GB] inherit

通过lvresize命令扩展Logical Volume

# lvresize -L +22.06G /dev/VolGroup00/LogVol00
  Rounding up size to full physical extent 22.06 GB
  Extending logical volume LogVol00 to 27.94 GB
  Logical volume LogVol00 successfully resized

调整完后，查看一下文件系统使用情况

#df -h 

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                      5.8G  3.5G  2.1G  63% /
/dev/sda1              99M   14M   81M  14% /boot
none                  506M     0  506M   0% /dev/shm

发现并没有没发生改变

通过ext2online命令在线resize文件系统

#ext2online /dev/mapper/VolGroup00-LogVol00

#df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                       28G  3.5G   23G  14% /
/dev/sda1              99M   14M   81M  14% /boot
none                  506M     0  506M   0% /dev/shm

大小调整成功！

检查分区

#e2fsck /dev/VolGroup00/LogVol00