一、調小虛擬機內存
調小虛擬機內存可以動態實現，不用關機
1.查看當前內存大小
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[root@kvm01 ~]# virsh dominfo vm1-clone | grep memory
Max memory: 786432 KiB
Used memory: 786432 KiB
2.設置虛擬機內存大小爲512MB
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[root@kvm01 ~]# virsh setmem vm1-clone 524288
3.再次查看當前內存大小
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[root@kvm01 ~]# virsh dominfo vm1-clone | grep memory
Max memory: 786432 KiB
Used memory: 524288 KiB
二、增大虛擬機內存、增加虛擬機CPU個數
增大虛擬機內存、增加虛擬機CPU個數需要首先關機虛擬機
1.關閉虛擬機
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virsh shutdown vm1-clone
2.編輯虛擬機配置文件
修改內存大小、vcpu個數
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virsh edit vm1-clone
......
<memory unit='KiB'>1048432</memory>
<currentMemory unit='KiB'>1048432</currentMemory>
<vcpu placement='static'>2</vcpu>
......
3.從配置文件啓動虛擬機
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virsh create /etc/libvirt/qemu/vm1-clone.xml
4.查看當前內存大小
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[root@kvm01 ~]# virsh dominfo vm1-clone | grep memory
Max memory: 1048432 KiB
Used memory: 524288 KiB
5.設置虛擬機內存大小爲1G
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[root@kvm01 ~]# virsh setmem vm1-clone 1048432
6.驗證
查看當前內存大小
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[root@kvm01 ~]# virsh dominfo vm1-clone | grep memory
Max memory: 1048432 KiB
Used memory: 1048432 KiB
查看當前CPU個數
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[root@kvm01 ~]# virsh dominfo vm1-clone | grep CPU
CPU(s): 2
CPU time: 15.0s
轉自：
http://blog.csdn.net/hnhuangyiyang/article/details/50902223