昨日对VM里的Linux进行了扩容，安装网络的教程一步一步来：
系统配置如图
扩展后执行fdisk -l查看是否成功
[root@localhost ~]# fdisk -l
Disk /dev/sda: 16.1 GB, 16106127360 bytes
255 heads, 63 sectors/track, 1958 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 6 48163+ 83 Linux
/dev/sda2 7 515 4088542+ 83 Linux
/dev/sda3 516 1239 5815530 83 Linux
/dev/sda4 1240 1305 530145 5 Extended
/dev/sda5 1240 1305 530113+ 82 Linux swap / Solaris
可见sda已经扩展成为16G，但是没分配给文件系统
继续执行fdisk /dev/sda进行新建磁盘
[root@localhost ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 1958.
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
No free sectors available
前面执行fdisk -l的时候明明最后才是1305柱面，而且应该有1958柱面，为什么说没有空闲的扇区。
再看看fdisk -l执行结果，原来是/dev/sda5分配了作为swap分区，找到原因了就容易解决。
1.关闭swap分区 # swapoff /dev/sda5
2.删除sda4和sda5.
[root@localhost ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 1958.
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): d
Partition number (1-5): 5
Command (m for help): d
Partition number (1-5): 4
3.建立扩展分区4，建立分区sda5，写入
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Selected partition 4
First cylinder (1240-1958, default 1240):
Using default value 1240
Last cylinder or +size or +sizeM or +sizeK (1240-1958, default 1958):
Using default value 1958
Command (m for help): n
First cylinder (1240-1958, default 1240):
Using default value 1240
Last cylinder or +size or +sizeM or +sizeK (1240-1958, default 1958):
Using default value 1958
Command (m for help): w
The partition table has been altered!
其他扩容继续参照网上的教程。