原来的虚拟机只分配了8G空间，用啊用啊的就满了。怎么办？
于是想过挂载硬盘，但是不太会弄，今天在hover(http://www.hoverlees.com/blog/)的帮助下，搞定了。

1、fdisk -l，看看挂载进来的硬件是什么？

Disk /dev/sda: 8589 MB, 8589935104 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777217 sectors
Units = sectors of 1 * 512512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006642a

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 16775167 8136705 5 Extended
/dev/sda5 501760 16775167 8136704 8e Linux LVM

Disk /dev/sdb: 25.8 GB, 25769803776 bytes
255 heads, 63 sectors/track, 3133 cylinders, total 50331648 sectors
Units = sectors of 1 * 512512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/mapper/webserver-root: 7763 MB, 7763656704 bytes
255 heads, 63 sectors/track, 943 cylinders, total 15163392 sectors
Units = sectors of 1 * 512512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/webserver-root doesn't contain a valid partition table

Disk /dev/mapper/webserver-swap_1: 532 MB, 532676608 bytes
255 heads, 63 sectors/track, 64 cylinders, total 1040384 sectors
Units = sectors of 1 * 512512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/webserver-swap_1 doesn't contain a valid partition table



2、将上面的红色部分的设备先格式化成某一类型的盘，输入：“mkfs.” 然后按TAB，出现：
mkfs.ext2 mkfs.ext3 mkfs.ext4 mkfs.ext4dev
为了更通用一点，我还是用了Ext3，所以我后来输入：mkfs.ext3 /dev/sdb1，返回：

mke2fs 1.41.14 (22-Dec-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
1572864 inodes, 6291200 blocks
314560 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
192 block groups
32768 blocks per group, 32768 fragments per group
8192 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 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.

3、mount到一个目录下，

root@webserver:/mnt# mount /dev/sdb1 /mnt

4、然后df看一下结果：

root@webserver:/mnt# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/webserver-root
7462608 4930416 2153108 70% /
udev 246512 4 246508 1% /dev
tmpfs 101524 576 100948 1% /run
none 5120 0 5120 0% /run/lock
none 253808 0 253808 0% /run/shm
/dev/sda1 233191 154710 66040 71% /boot
/dev/sdb1 24769916 176196 23335480 1% /mnt

一切就这样的完成了。
做个笔记。。。