转自：http://blog.csdn.net/liangliangdetianxia/article/details/37527767#comments

一、Vm虚拟机下扩展原有磁盘空间，详细步骤如下：

需注意以下几点： linux只能扩展磁盘容量而不能减小， 所填写的容量为总容量，即包含已分区的磁盘， 扩展容量时不能有快照哟，大家可以先把快照删除掉。

2.启动Linux，查看系统分区，并创建分区sda3，命令如下：红色字体命令，#后为注释：

[root@localhost~]#fdisk -l

Disk /dev/sda:32.2GB,32212254720 bytes

255heads,63sectors/track,3916cylinders

Units=cylindersof16065*512=8225280 bytes

DeviceBoot      Start      End        Blocks             Id       System

/dev/sda1  *        1            13         104391          83      Linux

/dev/sda2           14           1566    12474472+   8e      Linux LVM

#我的电脑有2个分区-sda1 sda2

[root@localhost~]#fdisk /dev/sda

Thenumberofcylindersforthisdiskissetto3916.

Thereisnothingwrongwiththat,butthisislargerthan1024,

andcouldincertainsetupscauseproblemswith:

1)softwarethatrunsatboottime(e.g.,oldversionsofLILO)

2)bootingandpartitioningsoftwarefromotherOSs

(e.g.,DOSFDISK,OS/2FDISK)

Command(mforhelp):m

Commandaction

a toggle a bootable flag

b edit bsd disk label

c toggle the dos compatibility flag

d delete a partition

l list known partition types

m print this menu

n add a new partition

o create a new empty DOS partition table

p print the partition table

q quit without saving changes

s create a new empty Sun disklabel

t change apartition's system id

u change display/entry units

v verify the partition table 

w write table to disk and exit

x extra functionality (expertsonly)