宿主机为24核cpu，64G内存，上面运行3台guest，因为业务的不确定性，不能提前确定多大性能服务器能够支持，所以开机为最小配置：4核 8G，以后随着业务增长动态调整CPU和内存

cat centos1

name = "centos1"

vcpus = 4

maxvcpus = 10

memory = 8192

maxmem = 24576

disk = [ "file:/var/xen/centos1.qcow2,"phy:/dev/sdc,xvdc,w"]

vif = [ "bridge=br0","bridge=br1" ]

on_reboot = "restart"

on_crash = "destroy"


修改内存：

xm mem-set centos1 16384     #调整centos1的内存为16G

xm mem-set centos1 24576     #调整centos1的内存为20G


修改cpu：

xm vcpu-list                            #查看cpu的使用

xm vcpu-set centos1 6            #修改centos1的cpu颗数


xm top                                   #查看当前各主机的状态



快照，做快照需要关机

xm save centos1 centos1.save

xm shutdown centos1

xm restore centos1.save