1、安装虚拟主机
更改root密码 
~#sudo passwd root
安装xen服务器
~#apt-get install ubuntu-xen-server
安装lvm2
~#apt-get install lvm2
~#reboot
2、准备LVM-backed VBDs
创建lvm分区
~# fdisk /dev/sda
The number of cylinders for this disk is set to 19457.
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
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
p
Selected partition 4
First cylinder (2008-19457, default 2008):
Using default value 2008
Last cylinder or +size or +sizeM or +sizeK (2008-19457, default 19457):
Using default value 19457
Command (m for help): t
Partition number (1-5): 4
Hex code (type L to list codes): 8e
Changed system type of partition 4 to 8e (Linux LVM)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
查看分区情况
~# fdisk /dev/sda -l
Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x624aa2e0
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          62      497983+  83  Linux
/dev/sda2              63        1278     9767520    5  Extended
/dev/sda3            1279        2007     5855692+  82  Linux swap / Solaris
/dev/sda4            2008       19457   140167125   8e  Linux LVM
/dev/sda5              63        1278     9767488+  83  Linux
重启系统，使刚划分的分区有效，否则你用pvcreate或其它工具对这个分区进行操作，会产生无此分区的错误
~#reboot
创建物理卷
~# pvcreate /dev/sda4
  Physical volume "/dev/sda4" successfully created
建立卷组
~# vgcreate vg1 /dev/sda4
  Volume group "vg1" successfully created
建立逻辑卷
~# lvcreate -L15G -nvbox01-winxp vg1
  Logical volume "vbox01-winxp" created
格式化刚建立的逻辑卷
~# mkfs.ext3 /dev/vg1/vbox01-winxp
mke2fs 1.40.8 (13-Mar-2008)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
983040 inodes, 3932160 blocks
196608 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4026531840
120 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
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:
done
This filesystem will be automatically checked every 27 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
挂载和卸载逻辑卷
~# mount /dev/vg1/vbox01-winxp /mnt
~# umount /mnt

3、建立虚拟客户机(winxp)
建立虚拟机配置文件
~# vi /etc/xen/vbox01-winxp.cfg
kernel='/usr/lib64/xen/boot/hvmloader'
builder='hvm'
name='vbox01-winxp'
device_model='/usr/lib64/xen/bin/qemu-dm'
disk=['phy:/dev/vg1/vbox01-winxp,hda,w','phy:/dev/loop0,hdc:cdrom,r']
boot='dc'
memory='512'
vcpus=3
vif=['type=ioemu,mac=00:21:41:e2:00:01,bridge=eth0']
on_poweroff='destroy'
on_reboot='restart'
on_crash='restart'
vnc=1
vnclisten='0.0.0.0'
vncdisplay=0
vncunused=1
vncpasswd='pass'
sdl=0
usb=1
usbdevice='mouse'
挂载ISO到模拟光驱
查找空闲loop设备
~# losetup -f
/dev/loop0
挂载ISO镜象到loop0
~# losetup -f /home/wxt/VRMPVOL_EN.iso
root@vbox01:~# losetup -a
/dev/loop0: [0805]:383528 (/home/wxt/VRMPVOL_EN.iso)
卸载模拟光驱
~# losetup -d /dev/loop0
重新挂载
~# losetup -f /home/wxt/VRMPVOL_EN.iso
开启虚拟客户机vbox01-winxp.cfg
~# xm create vbox01-winxp.cfg
Using config file "/etc/xen/vbox01-winxp.cfg".
Started domain vbox01-winxp
现在就可以用vnc连接到虚拟主机的IP，就可以使用虚拟客户机vbox01-winxp了
关掉vbox01-winxp
~# xm shutdown vbox01-winxp
4、利用dd复制虚拟客户机
# lvcreate -L15G -n vbox01-dcd vg1
  Logical volume "vbox01-dcd" created
# dd if=/dev/vg1/vbox01-winxp of=/dev/vg1/vbox01-dcd
31457280+0 records in
31457280+0 records out
16106127360 bytes (16 GB) copied, 1592.12 s, 10.1 MB/s
~# vi /etc/xen/vbox01-dcd.cfg
kernel='/usr/lib64/xen/boot/hvmloader'
builder='hvm'
guest_os_type='winxp'
name='vbox01-dcd'
device_model='/usr/lib64/xen/bin/qemu-dm'
disk=['phy:/dev/vg1/vbox01-dcd,hda,w','phy:/dev/loop0,hdc:cdrom,r']
boot='dc'
memory='512'
shadow_memory='32'
vcpus='3'
acpi=1
apic=1
vif=['type=ioemu,mac=00:21:41:e2:00:02,bridge=eth0']
on_poweroff='destroy'
on_reboot='restart'
vnclisten='0.0.0.0'
vnc=1
vncdisplay=1
vncunused=1
vncpasswd='password'
sdl=0
usb=1
usbdevice='mouse'
相对于被复制的主机，这里主要改四个地方
主机名vbox01-winxp => vbox01-dcd
虚拟硬盘phy:/dev/vg1/vbox01-winxp => phy:/dev/vg1/vbox01-dcd
网卡MAC地址00:21:41:e2:00:01 => 00:21:41:e2:00:02
VNC连接端口vncdisplay=0 => vncdisplay=1
vbox01-dcd开机
~#xm create vbox01-dcd.cfg
~# xm list
Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0  2702     3     r-----   2687.9
vbox01-dcd                                  23   512     2     r-----     14.7
vbox01-winxp                                22   512     2     -b----   1293.5
~# netstat -ln|grep 590[0-9]
tcp        0      0 0.0.0.0:5900            0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:5901            0.0.0.0:*               LISTEN
5、利用xm restore备份和恢复虚拟客户机
~# xm save vbox01-winxp /mnt/winxp.back
~# xm list
Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0   988     3     r-----  27570.4
~# ls -l /mnt/winxp.back
-rwxr-xr-x 1 root root 553009093 2009-02-02 21:15 /mnt/winxp.back
~# xm create vbox01-winxp.cfg
Using config file "./vbox01-winxp.cfg".
Started domain vbox01-winxp
在vbox01-winxp内新建文件等操作，更改虚拟机状态
~# xm shutdown vbox01-winxp
~# xm restore /mnt/winxp.back
~# xm list
Name                                        ID   Mem VCPUs      State   Time(s)
Domain-0                                     0   988     3     r-----  27603.9
vbox01-winxp                                57   512     2     r-----      5.8
进入vbox01-winxp系统，又恢复到备份点了

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