linux服务器里面可以安装多个虚拟机，一般我们采用的xen的虚拟机；当前服务器我们成为宿主机，在宿主机上安装多个虚拟机；
1. 在宿主机上安装虚拟机的方法：
2. 在宿主机上还原虚拟机
(1) 安装完虚拟机后，把虚拟机的硬盘压缩备份到一个目录中
(2) 压缩的硬盘文件在/mnt/pe_nfs/vm_img
[zengtai.csm@ecpm151052.cm3 /mnt/pe_nfs/vm_img/vm_img]$ ll
total 33866056
-rw-r--r-- 1 65534 65534 0 Aug 1 2011 aa
-rw-r--r-- 1 65534 65534 2264165361 Aug 1 2011 xexchange_installed_vm1.dd.gz
-rw-r--r-- 1 65534 65534 4878620444 Aug 1 2011 xexchange_installed_vm2.dd.gz
-rw-r--r-- 1 65534 65534 4940911480 Aug 1 2011 xexchange_installed_vm3.dd.gz
-rw-r--r-- 1 65534 65534 5165641551 Aug 1 2011 xexchange_installed_vm4.dd.gz
-rw-r--r-- 1 65534 65534 4099676357 Aug 1 2011 xexchange_installed_vm5.dd.gz
-rw-r--r-- 1 65534 65534 4032226728 Aug 1 2011 xexchange_installed_vm6.dd.gz
-rw-r--r-- 1 65534 65534 3805867479 Aug 1 2011 xexchange_installed_vm7.dd.gz
-rw-r--r-- 1 65534 65534 5457804555 Aug 1 2011 xexchange_installed_vm8.dd.gz
(3) 查看宿主机 ecpm151052.cm3 上面所有的虚拟机
[zengtai.csm@ecpm151052.cm3 ~]$ sudo xm list
Name ID Mem VCPUs State Time(s)
Domain-0 0 2585 8 r----- 242839.5
ecpmv152191_cm3 25 1700 1 -b---- 16876.8
ecpmv152192_cm3 26 1700 1 -b---- 320745.7
ecpmv152193_cm3 27 1700 1 -b---- 62111.1
ecpmv152194_cm3 28 1700 1 -b---- 133973.8
ecpmv152195_cm3 29 1700 1 -b---- 127182.3
ecpmv152196_cm3 1700 1 8772.2
ecpmv152197_cm3 35 1700 1 -b---- 26486.9
ecpmv152198_cm3 32 1700 1 -b---- 18668.5
(4) 把 目标虚拟机ecpmv152196_cm3 关闭
sudo virsh shutdown ecpmv152196_cm3
(5) 查询ecpmv152196_cm3 的硬盘挂载的宿主机磁盘路径
[zengtai.csm@ecpm151052.cm3 vm_img]$ sudo xm list --long ecpmv152196_cm3|grep dev
(device
(devid 0)
(device
(devid 51712)
(dev xvda)
(uname phy:/dev/sda11) --->ecpmv152196_cm3 的硬盘挂载在 /dev/sda11上面
(device
(devid 0)
(5) 恢复硬盘 病重启虚拟机
date;zcat xexchange_installed_vm6.dd.gz|sudo dd of=/dev/sda11;date
sudo virsh start ecpmv152196_cm3