首先說明一下情況，在VmWare上建立了一個Linux 虛擬機，當時硬盤只分配了20G用著用著發現硬盤不夠了需要擴展。

1.在VMware中將硬盤擴展到40G（這個鼠標點點就好了） 2.輸入fdisk /dev/sda看看硬盤有沒有變大
[root@localhost ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 5221.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): p
Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 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        2610    20860402+  8e  Linux LVM
這里我們發現一共有5221cylinders，可是結束卻在2610cylinders，這說明硬盤有空余，說明硬盤擴展成功。
3.新建分區
[root@localhost ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 5221.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): n //創建一個分區（卷）
Command action //問你是主分區還是擴展分區，我們輸入p代表主分區
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 3 //問你是第幾個分區，我這里前面有兩個分區了，輸入3表示建立第三個分區
First cylinder (2611-5221, default 2611):  //問你分區從哪個cylinder開始，保持默認
Using default value 2611
Last cylinder or +size or +sizeM or +sizeK (2611-5221, default 5221):
Using default value 5221 //問你分區在哪個cylinder結束，我們輸入回車，表示硬盤的最后一個cylinder
Command (m for help): t //輸入t我們修改剛剛建立的分區格式
Partition number (1-4): 3 //問我們改哪個分區，輸入3改第三個
Hex code (type L to list codes): 8e //改成什么格式的，輸入8e，表示Linux LVM格式
Changed system type of partition 3 to 8e (Linux LVM)
Command (m for help): p  //輸入p查看修改以后的狀態
Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 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        2610    20860402+  8e  Linux LVM
/dev/sda3            2611        5221    20972857+  8e  Linux LVM
Command (m for help): w //輸入w保存，這里可能要求重啟
4.對新建的分區格式化，輸入#mkfs.ext3 /dev/sda3
[root@localhost ~]# mkfs.ext3 /dev/sda3
mke2fs 1.39 (29-May-2006)
warning: 334 blocks unused.
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
2626560 inodes, 5242880 blocks
262160 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
160 block groups
32768 blocks per group, 32768 fragments per group
16416 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000
Writing inode tables: done                           
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
5.創建一個PV，輸入#pvcreate /dev/sda3
[root@localhost ~]# pvcreate /dev/sda3
  Physical volume "/dev/sda3" successfully created
6.將建立好的PV加入到現有的VG中，輸入#vgextend VolGroup00 /dev/sda3 （注意這里第二個參數為VG的名字）
[root@localhost ~]# vgextend VolGroup00 /dev/sda3
  Volume group "VolGroup00" successfully extended
7.擴展LV，輸入#lvextend -L +20G /dev/VolGroup00/LogVol00
[root@localhost ~]# lvextend -L +20G /dev/VolGroup00/LogVol00
  Extending logical volume LogVol00 to 35.94 GB
  Logical volume LogVol00 successfully resized
8.從新識別一下LV的容量，輸入#resize2fs /dev/VolGroup00/LogVol00
[root@localhost ~]# resize2fs /dev/VolGroup00/LogVol00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/LogVol00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/LogVol00 to 9420800 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 9420800 blocks long.

9.至此擴展就已經成功了，你可以輸入df -l查看新的容量
[root@localhost ~]# df -l
文件系統               1K-塊        已用     可用 已用% 掛載點
/dev/mapper/VolGroup00-LogVol00
                      36505664  15045120  19579916  44% /
/dev/sda1               101086     12097     83770  13% /boot
tmpfs                  1037748         0   1037748   0% /dev/shm