KVM虚拟化
KVM虚拟化
KVM(Kernel-Based Virtual Machines)是一个基于Linux内核的虚拟化技术, 可以直接将Linux内核转换为Hypervisor（系统管理程序）从而使得Linux内核能够直接管理虚拟机, 直接调用Linux内核中的内存管理、进程管理子系统来管理虚拟机。
KVM的虚拟化需要硬件支持（如Intel VT技术或者AMD V技术)。是基于硬件的完全虚拟化。而Xen早期则是基于软件模拟的Para-Virtualization，新版本则是基于硬件支持的完全虚拟化。但Xen本身有自己的进程调度器、存储管理模块等，所以代码较为庞大。广为流传的商业系统虚拟化软件VMware ESX系列是基于软件模拟的Full-Virtualization。
任务一、安装KVM
1.创建虚拟机
虚拟机内存至少设置成 2 GB，在“硬件”选项卡中单击“处理器”， 在虚拟化引擎中勾选如红框内所示选项
接下来，我们添加硬盘，添加一个 50GB 左右大小的就可以
虚拟机设置完成之后如下图：
配置完成之后，启动虚拟机（配置网卡、关闭防火墙并设置开机不自启、挂载yum源）
配置网卡：
# ip addr
# vi /etc/sysconfig/network-scripts/ifcfg-ens33
# systemctl restart network
# ip addr
关闭防火墙，并设置开机不自启：
# systemctl stop firewalld
# systemctl disable firewalld
# setenforce 0
# vi /etc/selinux/config //换成disabled
挂载yum源：
# mkdir /opt/centos
# mount /dev/sr0 /opt/centos
# mv /etc/yum.repos.d/* /media/
# vi /etc/yum.repos.d/local.repo
[centos]
name=centos
baseurl=file:///opt/centos
gpgcheck=0
enabled=1
# yum clean all
# yum repolist
2.检查CPU参数
查看以下内存是否更改成功：
# free
total used free shared buff/cache available
Mem: 1868688 125360 1582372 8752 160956 1584208
Swap: 097148 0 2097148
检查CPU是否开启虚拟化支持：
# grep -Ei 'vmx|svm' /proc/cpuinfo
//vmx为英特尔的cpu；svm为AMD的cpu。
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb
rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc
eagerfpu pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe
popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm
3dnowprefetch arat tpr_shadow vnmi ept vpid fsgsbase tsc_adjust bmi1 avx2
smep bmi2 invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xsaves
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm
constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu
pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt
tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm
3dnowprefetch arat tpr_shadow vnmi ept vpid fsgsbase tsc_adjust bmi1 avx2
smep bmi2 invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xsaves
如果显示为空，就要检查虚拟机设置是否打“√”
3.挂载新磁盘
使用lsblk命令，检查虚拟机是否新增一块50 GB的磁盘：
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 19.5G 0 part
├─centos-root 253:0 0 17.5G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [ SWAP]
sdb 8:16 0 50G 0 disk
sr0 11:0 1 4G 0 rom
我们可以看到确实新增了一块磁盘名为sdb。
接下来格式化这块磁盘，格式化成ext4格式：
# mkfs.ext4 /dev/sdb
mke2fs 1.42.9 (28-Dec-2013)
/dev/sdb is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
3276800 inodes, 13107200 blocks
655360 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2162163712
400 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, 7962624, 11239424
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:
done
# blkid /dev/sdb
//blkid+磁盘：查看磁盘信息
/dev/sdb: UUID="dab6d659-e334-41ed-a15a-9
6ce05b48c1a" TYPE="ext4"
格式化完成后，我们挂载磁盘，先创建挂载目录/kvm_data，然后进行挂载：
# mkdir /kvm_data
# mount /dev/sdb /kvm_data/
这种方式挂载，重启虚拟机后，需要再次重新挂载，我们为了方便开机后可以自动挂载，编写/etc/fstab文件，添加文件最末一行：
# vi /etc/fstab
# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Thu Aug 22 22:51:46 2019
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=34f3cd91-b7f0-44dd-9334-2bb66e939898 /boot xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
/dev/sdb /kvm_data ext4 defaults 0 0
4.安装KVM
使用Yum进行安装KVM：
# yum install -y virt-* libvirt bridge-utils qemu-img
…………
Complete!
任务二、启动KVM
1.配置网卡
增加桥接网卡ifcfg-br0，命令如下：
[root@kvm ~]# cd /etc/sysconfig/network-scripts/
[root@kvm network-scripts]# cp ifcfg-ens33 ifcfg-br0
//ifcfg-ens33为配置IP的网卡，网卡可能不同
修改桥接网卡ifcfg-br0的内容：
[root@kvm network-scripts]# vi ifcfg-br0
[root@kvm network-scripts]# cat ifcfg-br0
TYPE=Bridge
BOOTPROTO=none
NAME=br0
DEVICE=br0
ONBOOT=yes
IPADDR=192.168.233.5
NETMASK=255.255.255.0
GATEWAY=192.168.233.2
DNS1=114.114.114.114
DNS2=8.8.8.8
修改NAT网卡ifcfg-ens33：
[root@kvm network-scripts]# vi ifcfg-ens33
[root@kvm network-scripts]# cat ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=none
NAME=ens33
DEVICE=ens33
ONBOOT=yes
BRIDGE=br0
修改完成网卡内容后，重新启动网卡服务并查看网卡信息：
[root@kvm network-scripts]# service network restart
Restarting network (via systemctl): [ OK ]
[root@kvm network-scripts]# ifconfig
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.16.5 netmask 255.255.255.0 broadcast
192.168.16.255
inet6 fe80::20c:29ff:fe8d:1f90 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:8d:1f:90 txqueuelen 0 (Ethernet)
RX packets 90 bytes 7092 (6.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 38 bytes 3604 (3.5 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>
mtu 1500
ether 00:0c:29:8d:1f:90 txqueuelen 1000 (Ethernet)
RX packets 126287 bytes 182444678 (173.9 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 32532 bytes 2953477 (2.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
可以清楚的看到br0网卡出现并且带有IP，而以前的ens33网卡则没有IP，网卡配置完成
2.启动libvirtd服务
首先检查KVM模块是否加载：
[root@kvm network-scripts]# lsmod|grep kvm
kvm_intel 162153 0
kvm 525259 1 kvm_intel
启动libvirtd并检查是否成功启动：
[root@kvm network-scripts]# systemctl start libvirtd
[root@kvm network-scripts]# ps -ef |grep libvirt
root 17270 1 1 04:36 ? 00:00:00 /usr/sbin/libvirtd
nobody 17383 1 0 04:36 ? 00:00:00
/usr/sbin/dnsmasq --conf-
file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-
script=/usr/libexec/libvirt_leaseshelper
root 17384 17383 0 04:36 ? 00:00:00
/usr/sbin/dnsmasq --conf-
file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-
script=/usr/libexec/libvirt_leaseshelper
root 17416 2264 0 04:36 pts/0 00:00:00 grep --
color=auto libvirt
启动成功后，使用brctl命令可以看到两个网卡，如下代码所示：
[root@kvm ~]# cd
[root@kvm ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c298d1f90 no ens33
virbr0 8000.525400c7e229 yes virbr0-nic
3.安装CentOS 7
CentOS7镜像下载地址：
http://mirrors.163.com/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-2003.iso
首先，通过SCRT上传CentOS 7镜像到/tmp目录下，如果没有镜像的可以自行下载。上传后，使用ll命令查看/tmp目录下是否存在CentOS 7镜像文件：
[root@kvm ~]# ll /tmp/
total 4228096
-rw-r--r-- 1 root root 4329570304 Apr 15 2016 CentOS-7- x86_64-DVD-1511.iso
命令解释：
l --name：指定虚拟机的名称。
l --memory：指定分配给虚拟机的内存资源大小。
l maxmemory：指定可调节的最大内存资源大小，因为KVM支持热调整虚拟机的资源。
l --vcpus：指定分配给虚拟机的CPU核心数量。
l maxvcpus：指定可调节的最大CPU核心数量。
l --os-type：指定虚拟机安装的操作系统类型。
l --os-variant：指定系统的发行版本。
l --location：指定ISO镜像文件所在的路径，支持使用网络资源路径，也就是说可以使用URL。
l --disk path：指定虚拟硬盘所存放的路径及名称，size则是指定该硬盘的可用大小，单位是G。
l --bridge：指定使用哪一个桥接网卡，也就是说使用桥接的网络模式。
l --graphics：指定是否开启图形。
l --console：定义终端的属性，target_type 则是定义终端的类型。
l --extra-args：定义终端额外的参数。
镜像存在，接下来使用virt-install进行CentOS 7的安装： [root@kvm ~]# virt-install --name=test --memory=512,maxmemory=1024 --vcpus=1,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/tmp/CentOS-7-x86_64-DVD-1511.iso --disk path=/kvm_data/test.img,size=10 --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args="console=tty0 console=ttyS0" 打完上面那条命令后，等一会，就可以看见下面这段命令，这是系统基础设置，带[!]基本都是需要配置的，接下来我们开始配置“Timezone settings”，输入“2”，按Enter键： Starting installer, one moment... anaconda 21.48.22.56-1 for CentOS 7 started. * installation log files are stored in /tmp during the installation * shell is available on TTY2 * when reporting a bug add logs from /tmp as separate text/plain attachments 17:01:51 Not asking for VNC because we don't have a network ================================================================================ ================================================================================ Installation 1) [x] Language settings 2) [!] Timezone settings (English (United States)) (Timezone is not set.) 3) [!] Installation source 4) [!] Software selection (Processing...) (Processing...) 5) [!] Installation Destination 6) [x] Kdump (No disks selected) (Kdump is enabled) 7) [ ] Network configuration 8) [!] Root password (Not connected) (Password is not set.) 9) [!] User creation (No user will be created) Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 2 ===================================================================== “Timezone settings”时区设置选择 5) Asia亚洲，再选择城市 62) Shanghai上海，命令如下： Timezone settings Available regions 1) Africa 6) Atlantic 10) Pacific 2) America 7) Australia 11) US 3) Antarctica 8) Europe 12) Etc 4) Arctic 9) Indian 5) Asia Please select the timezone. Use numbers or type names directly [b to region list, q to quit]: 5 ================================================================================ ================================================================================ Timezone settings Available timezones in region Asia 1) Aden 28) Irkutsk 54) Pyongyang 2) Almaty 29) Jakarta 55) Qatar 3) Amman 30) Jayapura 56) Qyzylorda 4) Anadyr 31) Jerusalem 57) Rangoon 5) Aqtau 32) Kabul 58) Riyadh 6) Aqtobe 33) Kamchatka 59) Sakhalin 7) Ashgabat 34) Karachi 60) Samarkand 8) Baghdad 35) Kathmandu 61) Seoul 9) Bahrain 36) Khandyga 62) Shanghai 10) Baku 37) Kolkata 63) Singapore 11) Bangkok 38)Krasnoyarsk 64) Srednekolymsk 12) Beirut 39) Kuala_Lumpur 65) Taipei 13) Bishkek 40) Kuching 66) Tashkent 14) Brunei 41) Kuwait 67) Tbilisi 15) Chita 42) Macau 68) Tehran 16) Choibalsan 43) Magadan 69) Thimphu 17) Colombo 44) Makassar 70) Tokyo 18) Damascus 45) Manila 71) Ulaanbaatar 19) Dhaka 46) Muscat 72) Urumqi 20) Dili 47) Nicosia 73) Ust-Nera 21) Dubai 48) Novokuznetsk 74) Vientiane 22) Dushanbe 49) Novosibirsk 75) Vladivostok Press ENTER to continue 23) Gaza 50) Omsk 76) Yakutsk 24) Hebron 51) Oral 77) Yekaterinburg 25) Ho_Chi_Minh 52) Phnom_Penh 78) Yerevan 26) Hong_Kong 53) Pontianak 27) Hovd Please select the timezone. Use numbers or type names directly [b to region list, q to quit]: 62 ================================================================================ 输入完毕后，可以发现2的[!]变成了[x]，证明配置完毕。 接下来我们配置“Software selection”，选择“4”，在选择“c”，因为默认就是minimalinstall，按Enter键，命令如下： Installation 1) [x] Language settings 2) [x] Timezone settings (English (United States)) (Asia/Shanghai timezone) 3) [x] Installation source 4) [!] Software selection (Local media) (Minimal Install) 5) [!] Installation Destination 6) [x] Kdump (No disks selected) (Kdump is enabled) 7) [ ] Network configuration 8) [!] Root password (Not connected) (Password is not set.) 9) [!] User creation (No user will be created) Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 4 ================================================================================ ================================================================================ Base environment Software selection Base environment 1) [x] Minimal Install 7) [ ] Server with GUI 2) [ ] Compute Node 8) [ ] GNOME Desktop 3) [ ] Infrastructure Server 9) [ ] KDE Plasma Workspaces 4) [ ] File and Print Server 10) [ ] Development and Creative Work 5) [ ] Basic Web Server station 6) [ ] Virtualization Host Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c 接下来我们配置“Installation Destination”，选择“5”，其余的依次选择“c”，按Enter键，命令如下： Installation 1) [x] Language settings 2) [x] Timezone settings (English (United States)) (Asia/Shanghai timezone) 3) [!] Installation source 4) [!] Software selection (Processing...) (Processing...) 5) [!] Installation Destination 6) [x] Kdump (No disks selected) (Kdump is enabled) 7) [ ] Network configuration 8) [!] Root password (Not connected) (Password is not set.) 9) [!] User creation (No user will be created) Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 5 ================================================================================ ================================================================================ Probing storage... Installation Destination [x] 1) : 10 GiB (vda) 1 disk selected; 10 GiB capacity; 10 GiB free ... Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c ================================================================================ ================================================================================ Autopartitioning Options [ ] 1) Replace Existing Linux system(s) [x] 2) Use All Space [ ] 3) Use Free Space Installation requires partitioning of your hard drive. Select what space to use for the install target. Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c ================================================================================ ================================================================================ Partition Scheme Options [ ] 1) Standard Partition [ ] 2) Btrfs [x] 3) LVM [ ] 4) LVM Thin Provisioning Select a partition scheme configuration. Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c Generating updated storage configuration Checking storage configuration... ================================================================================ ================================================================================ 接下来配置“Root password”，选择8，按Enter键，命令如下： Installation 1) [x] Language settings 2) [x] Timezone settings (English (United States)) (Asia/Shanghai timezone) 3) [x] Installation source 4) [x] Software selection (Local media) (Minimal Install) 5) [x] Installation Destination 6) [x] Kdump (Automatic partitioning selecte (Kdump is enabled) d) 8) [!] Root password 7) [ ] Network configuration (Password is not set.) (Not connected) 9) [!] User creation (No user will be created) Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 8 ================================================================================ ================================================================================ Please select new root password. You will have to type it twice. 依次输入两次密码，密码相同，我设置的为123456： Password: 123456 //密码为密文，不显示。 Password (confirm): 123456 ================================================================================ ================================================================================ Question You have provided a weak password: The password fails the dictionary check - it is too simplistic/systematic Would you like to use it anyway? //这句话的意思：你的密码太过简单，是否使用它，输入yes即可。 Please respond 'yes' or 'no': yes ========================================================= ========================================================= 配置完成，选择“b”，按Enter键后，开始安装： Installation 1) [x] Language settings 2) [x] Timezone settings (English (United States)) (Asia/Shanghai timezone) 3) [x] Installation source 4) [x] Software selection (Local media) (Minimal Install) 5) [x] Installation Destination 6) [x] Kdump (Automatic partitioning selecte (Kdump is enabled) d) 8) [x] Root password 7) [ ] Network configuration (Password is set.) (Not connected) 9) [ ] User creation (No user will be created) Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: b ================================================================================ ================================================================================ Progress Setting up the installation environment . Creating disklabel on /dev/vda . Creating xfs on /dev/vda1 . Creating lvmpv on /dev/vda2 . Creating swap on /dev/mapper/centos-swap . …………………… Installing readline (34/297) Installing gawk (35/297) Installing elfutils-libelf (36/297) Installing libgpg-error (37/297) Installing libffi (38/297) Installing libattr (39/297) Installing libacl (40/297) Installing libcap (41/297) Installing libgcrypt (42/297) Installing cpio (43/297) Installing libxml2 (44/297) Installing libnl3 (45/297) Installing expat (46/297) Installing p11-kit (47/297) …………………… . Performing post-installation setup tasks . Configuring installed system . Writing network configuration . Creating users . Configuring addons . Generating initramfs . Running post-installation scripts . Use of this product is subject to the license agreement found at /usr/share/centos-release/EULA Installation complete. Press return to quit //按回车 …………………… CentOS Linux 7 (Core) Kernel 3.10.0-327.el7.x86_64 on an x86_64 localhost login: root Password: 123456 [root@localhost ~]# //按“Ctrl+]”键，退出终端，回到宿主机。 [root@kvm ~]#
CentOS安装完成
任务三、虚拟机管理
1.KVM基本管理
完成虚拟机安装，已经退回到宿主机，接下来我们来通过宿主机virsh命令进行管理刚才安装的CentOS 7虚拟机
查看虚拟机列表：
[root@kvm ~]# virsh list
//查看虚拟机列表，只能看到正在运行的虚拟机
Id Name State
----------------------------------------------------
2 test running
[root@kvm ~]# virsh list --all
//查看虚拟机列表，包括未运行的虚拟机
Id Name State
----------------------------------------------------
2 test running
进入指定的虚拟，命令如下：
[root@kvm ~]# virsh console test
Connected to domain test
Escape character is ^]
//如果迟迟未动敲下回车就ok，下面就是正常登录时需要输入的用户名密码
CentOS Linux 7 (Core)
Kernel 3.10.0-327.el7.x86_64 on an x86_64
localhost login:
若发生以下报错信息，命令如下：
[root@kvm ~]# virsh console test
Connected to domain test
Escape character is ^]
error: operation failed: Active console session exists for this domain
解决方式，命令如下：
[root@kvm ~]# ps -ef |grep console
root 11167 10987 0 01:55 tty1 00:00:00 virsh console
test
root 16017 15750 0 10:01 pts/1 00:00:00 grep --
color=auto console
[root@kvm ~]# kill -9 11167
vrish常用命令，命令如下：
virsh shutdown test
//关闭虚拟机
virsh start test
//开启虚拟机
virsh destroy test
//类似stop，这个是强制停止
virsh undefine test
//彻底销毁虚拟机，会删除虚拟机配置文件，virsh list --all就看不到
virsh autostart test
//宿主机开机该虚拟机也开机
virsh autostart --disable test
//解除开机启动
virsh suspend test
//挂起
virsh resume test
2.克隆虚拟机
克隆虚拟机之前，要先关闭虚拟机，不然会提示这种错误：
[root@kvm ~]# virt-clone --original test --name test02 --file /kvm_data/test02.img
ERROR Domain with devices to clone must be paused or shutoff.
关闭虚拟机后，再次进行克隆：
[root@kvm ~]# virsh shutdown test
Domain test is being shutdown
[root@kvm ~]# virt-clone --original test --name test02 --file /kvm_data/test02.img
Allocating 'test02.img' 3%
[= ] 20 MB/s | 365 MB 00:08:23 ETA
//开始克隆
[root@kvm ~]# virt-clone --original test --name test02 --file /kvm_data/test02.img
Allocating 'test02.img' | 10 GB 00:00:35
Clone 'test02' created successfully.
//克隆完成且成功
命令解释：
--original：指定克隆源虚拟机。
--name：指定克隆后的虚拟机名字。
--file：指定目标虚拟机的虚拟磁盘文件。
查看虚拟机配置文件/etc/libvirt/qemu/,看是否增加test02.xml文件：
[root@kvm ~]# ls /etc/libvirt/qemu/
networks test02.xml test.xml
启动刚刚克隆的虚拟机test02，首先查看虚拟机列表，然后启动克隆的虚拟机test02：
[root@kvm ~]# virsh list --all
Id Name State
----------------------------------------------------
- test shut off
- test02 shut off
[root@kvm ~]# virsh start test02
Domain test02 started
3.快照管理
快照是在我们使用Vmware的时候，很常用的一个功能，它可以回到之前的某一状态，在KVM中RAW格式的虚拟磁盘不支持做快照，qcow2支持
创建快照，命令如下：
[root@kvm ~]# virsh snapshot-create test
Domain snapshot 1588485687 created
查看test.img信息，同时会查看到快照列表：
[root@kvm ~]# qemu-img info /kvm_data/test.img
image: /kvm_data/test.img
file format: qcow2
virtual size: 10G (10737418240 bytes)
disk size: 1.1G
cluster_size: 65536
Snapshot list:
ID TAG VM SIZE DATE VM CLOCK
1 1588485687 0 2020-05-03 14:01:27
00:00:00.000
Format specific information:
compat: 1.1
lazy refcounts: true
列出所有快照，命令如下：
[root@kvm ~]# virsh snapshot-list test
Name Creation Time State
------------------------------------------------------------
1588485687 2020-05-03 14:01:27 +0800 shutoff
查看当前快照版本，命令如下：
[root@kvm ~]# virsh snapshot-current test
<domainsnapshot>
<name>1588485687</name>
<state>shutoff</state>
<creationTime>1588485687</creationTime>
<memory snapshot='no'/>
<disks>
<disk name='vda' snapshot='internal'/>
<disk name='hda' snapshot='no'/>
</disks>
<domain type='kvm'>
<name>test</name>
<uuid>49d7cb9c-20dc-42dd-a260-01532b5132e5</uuid>
<memory unit='KiB'>1048576</memory>
<currentMemory unit='KiB'>524288</currentMemory>
<vcpu placement='static' current='1'>2</vcpu>
<os>
..........
..........
</serial>
<console type='pty'>
<target type='serial' port='0'/>
</console>
<channel type='unix'>
<target type='virtio' name='org.qemu.guest_agent.0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='mouse' bus='ps2'/>
<input type='keyboard' bus='ps2'/>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</memballoon>
<rng model='virtio'>
<backend model='random'>/dev/urandom</backend>
<address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
</rng>
</devices>
</domain>
</domainsnapshot>
查看所有快照配置文件，命令如下：
[root@kvm ~]# ls /var/lib/libvirt/qemu/snapshot/test/
1588485687.xml
恢复指定快照，命令如下：
[root@kvm ~]# virsh snapshot-revert test 1588485687
删除指定快照，命令如下：
[root@kvm ~]# virsh snapshot-delete test 1588485687
Domain snapshot 1588485687 deleted
4.磁盘格式
查看虚拟磁盘格式，命令如下：
[root@kvm ~]# qemu-img info /kvm_data/test.img
image: /kvm_data/test.img
file format: qcow2
virtual size: 10G (10737418240 bytes)
disk size: 1.1G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: true
创建2 GB的RAW格式磁盘，命令如下：
[root@kvm ~]# qemu-img create -f raw /kvm_data/test_1.img 2G
Formatting '/kvm_data/test_1.img', fmt=raw
size=2147483648
RAW格式的磁盘转换为qcow2格式：
[root@kvm ~]# qemu-img convert -O qcow2 /kvm_data/test_1.img /kvm_data/test_1.qcow2
查看test1.img大小，命令如下：
[root@kvm ~]# ls -lh /kvm_data/test_1.img
-rw-r--r-- 1 root root 2.0G May 3 15:11 /kvm_data/test_1.img
[root@kvm ~]# ls -lh /kvm_data/test_1.qcow2
-rw-r--r-- 1 root root 193K May 3 15:38
/kvm_data/test_1.qcow2
//可以看到qcow2文件比较小，raw文件大小和我们指定空间大小一样是2G
//raw格式的磁盘性能比qcow2要好，但是raw格式的磁盘无法做快照
将test02转成raw格式，命令如下：
[root@kvm ~]# qemu-img convert -O raw /kvm_data/test02.img /kvm_data/test02_2.raw
更改磁盘格式和文件路径，然后启动test02虚拟机：
[root@kvm ~]# virsh edit test02
…………
<disk type='file' device='disk'>
<driver name='qemu' type='qcow'/>
<source file='/kvm_data/test02.img'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
//找到上面这部分将qcow修改为raw，/kvm_data/test02.img改为/kvm_data/test02_2.raw
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/kvm_data/test02_2.raw'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
………………
查看磁盘所属用户和组，命令如下：
[root@kvm ~]# ls -l /kvm_data/
total 3310628
drwx------ 2 root root 16384 Apr 29 00:20 lost+found
-rw-r--r-- 1 root root 10737418240 May 3 16:14 test02_2.raw
-rw------- 1 root root 1133772800 May 3 16:02 test02.img
-rw-r--r-- 1 root root 2147483648 May 3 15:11 test_1.img
-rw-r--r-- 1 root root 197120 May 3 16:05 test_1.qcow2
-rw------- 1 root root 10739384832 May 3 14:14 test.img
启动虚拟机test02，然后再次查看磁盘所属用户和组：
[root@kvm ~]# virsh start test02
Domain test02 started
[root@kvm ~]# ls -l /kvm_data/
total 3310628
drwx------ 2 root root 16384 Apr 29 00:20 lost+found
-rw-r--r-- 1 qemu qemu 10737418240 May 3 16:14 test02_2.raw
-rw------- 1 root root 1133772800 May 3 16:02 test02.img
-rw-r--r-- 1 root root 2147483648 May 3 15:11 test_1.img
-rw-r--r-- 1 root root 197120 May 3 16:05 test_1.qcow2
-rw------- 1 root root 10739384832 May 3 14:14 test.img
//启动后所属组变化成qemu的是test02_2.raw，证明这个磁盘正在被使用
5.磁盘扩容
在这里磁盘一共有两种格式，一种是RAW格式，一种是qcow2格式，接下来我们分别给这两种磁盘格式进行扩容
首先扩容RAW格式，命令如下：
[root@kvm ~]# qemu-img resize /kvm_data/test02_2.raw +2G
Image resized.
查看test02_2.raw信息，命令如下：
[root@kvm ~]# qemu-img info /kvm_data/test02_2.raw
image: /kvm_data/test02_2.raw
file format: raw
virtual size: 12G (12884901888 bytes)
disk size: 1.0G
进入虚拟机test02，使用fdisk -l查看磁盘，命令如下：
[root@kvm ~]# virsh console test02
[root@localhost ~]# fdisk -l
Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
//可以看到磁盘还是10 GB
退出终端，关闭test02虚拟机，重新启动，然后再次进入虚拟机test02，使用fdisk -l查看磁盘：
[root@kvm ~]# virsh destroy test02
Domain test02 destroyed
[root@kvm ~]# virsh start test02
Domain test02 started
[root@kvm ~]# virsh console test02
[root@localhost ~]# fdisk -l
Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
可以看到已经变成12 GB了
接下来分区：
[root@localhost ~]# fdisk /dev/vda
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
//新建分区
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p
Partition number (3,4, default 3):
//按Enter键
First sector (20971520-25165823, default 20971520):
//按Enter键
Using default value 20971520
Last sector, +sectors or +size{K,M,G} (20971520-25165823, default 25165823):
//按Enter键
Using default value 25165823
Partition 3 of type Linux and of size 2 GiB is set
Command (m for help): p
//查看分区列表
Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
/dev/vda3 20971520 25165823 2097152 83 Linux
Command (m for help): w
//保存退出并退出终端
除了对已有磁盘扩容外，还可以额外增加磁盘：
[root@kvm ~]# qemu-img create -f raw /kvm_data/test02_3.raw 5G
Formatting '/kvm_data/test02_3.raw', fmt=raw size=5368709120
使用virsh edit编辑test02虚拟机，将新磁盘增加到test02虚拟机：
[root@kvm ~]# virsh edit test02
………………
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/kvm_data/test02_2.raw'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</disk>
//找到这一部分内容，在下面增加以下内容
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/kvm_data/test02_3.raw'/>
<target dev='vdb' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x09'
function='0x0'/>
</disk>
………………
关闭test02虚拟机，重新启动，然后进入该虚拟机，使用fdisk -l查看磁盘：
[root@kvm ~]# virsh destroy test02
Domain test02 destroyed
[root@kvm ~]# virsh start test02
Domain test02 started
[root@kvm ~]# virsh console test02
[root@localhost ~]# fdisk -l
Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
/dev/vda3 20971520 25165823 2097152 83 Linux
Disk /dev/vdb: 5368 MB, 5368709120 bytes, 10485760 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
可以看到多了一块5GB的磁盘，退出终端。
接下来，我们扩容qcow2格式的磁盘，命令如下：
[root@kvm ~]# qemu-img resize /kvm_data/test.img +2G
Image resized.
//若提示qemu-img: Can't resize an image which has snapshots，需要删除快照
查看test.img信息，命令如下：
[root@kvm ~]# qemu-img info /kvm_data/test.img
image: /kvm_data/test.img
file format: qcow2
virtual size: 12G (12884901888 bytes)
disk size: 1.1G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: true
关闭test虚拟机，重新启动，然后再次进入虚拟机test02，使用fdisk -l查看磁盘：
[root@kvm ~]# virsh destroy test
Domain test destroyed
[root@kvm ~]# virsh start test
Domain test started
[root@kvm ~]# virsh console test
[root@localhost ~]# fdisk -l
Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
分区新增加的2 GB磁盘，命令如下：
[root@localhost ~]# fdisk /dev/vda
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p
Partition number (3,4, default 3):
First sector (20971520-25165823, default 20971520):
Using default value 20971520
Last sector, +sectors or +size{K,M,G} (20971520-25165823, default 25165823):
Using default value 25165823
Partition 3 of type Linux and of size 2 GiB is set
Command (m for help): w
保存并退出终端
新增一块qcow2格式的磁盘，命令如下：
[root@kvm ~]# qemu-img create -f qcow2 /kvm_data/test_2.img 5G
Formatting '/kvm_data/test_2.img', fmt=qcow2
size=5368709120 encryption=off cluster_size=65536
lazy_refcounts=off
使用virsh edit编辑test虚拟机，将新磁盘增加到test虚拟机，命令如下：
[root@kvm ~]# virsh edit test
………………
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/kvm_data/test.img'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
//找到这一部分内容，在下面增加以下内容
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/kvm_data/test_2.img'/>
<target dev='vdb' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
</disk>
………………
关闭test虚拟机，重新启动，然后进入该虚拟机，使用fdisk -l查看磁盘：
[root@kvm ~]# virsh destroy test
Domain test destroyed
[root@kvm ~]# virsh start test
Domain test started
[root@kvm ~]# virsh console test
[root@localhost ~]# fdisk -l
Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0005b865
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 1026047 512000 83 Linux
/dev/vda2 1026048 20971519 9972736 8e Linux LVM
/dev/vda3 20971520 25165823 2097152 83 Linux
Disk /dev/vdb: 5368 MB, 5368709120 bytes, 10485760 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
退出终端
6.调整 CPU 内存、网卡
查看虚拟机配置信息，命令如下：
[root@kvm ~]# virsh dominfo test
Id: 8
Name: test
UUID: 49d7cb9c-20dc-42dd-a260-01532b5132e5
OS Type: hvm
State: running
CPU(s): 1
CPU time: 20.8s
Max memory: 1048576 KiB
Used memory: 524288 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
编辑虚拟机内存，命令如下：
[root@kvm ~]# virsh edit test
…………
<memory unit='KiB'>1048576</memory>
//最大内存
<currentMemory unit='KiB'>524288</currentMemory>
//可用内存
<vcpu placement='static' current='1'>2</vcpu>
//最大cpu
………………
//将以上内容修改为如下内容
…………
<memory unit='KiB'>1048576</memory>
<currentMemory unit='KiB'>624288</currentMemory>
<vcpu placement='static' current='1'>2</vcpu>
…………
关闭虚拟机，重启动虚拟机，命令如下：
[root@kvm ~]# virsh destroy test
Domain test destroyed
[root@kvm ~]# virsh start test
Domain test started
查看虚拟机配置信息，看是否修改成功，命令如下：
[root@kvm ~]# virsh dominfo test
Id: 10
Name: test
UUID: 49d7cb9c-20dc-42dd-a260-01532b5132e5
OS Type: hvm
State: running
CPU(s): 1
CPU time: 21.4s
Max memory: 1048576 KiB
Used memory: 624288 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
除了这种修改方式之外，还有一种动态修改，命令如下：
[root@kvm ~]# virsh setmem test 800m
//动态修改内存
[root@kvm ~]# virsh setvcpus test 2
//动态修改cpu，只可以增加不可以减少
查看配置信息，看是否修改成功，命令如下：
[root@kvm ~]# virsh dominfo test
Id: 10
Name: test
UUID: 49d7cb9c-20dc-42dd-a260-01532b5132e5
OS Type: hvm
State: running
CPU(s): 2
CPU time: 22.8s
Max memory: 1048576 KiB
Used memory: 819200 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
[root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test.xml
//需要把配置写入到配置文件里
查看网卡列表，命令如下：
[root@kvm ~]# virsh domiflist test
Interface Type Source Model MAC
-------------------------------------------------------
vnet1 bridge br0 virtio 52:54:00:93:bf:07
增加一块新的网卡，并设置为NAT网络模式（virbr0类似VMware的VMnet8），这里如果写--source br0，则网络模式为桥接：
[root@kvm ~]# virsh attach-interface test --type bridge --source virbr0
Interface attached successfully
[root@kvm ~]# virsh domiflist test
Interface Type Source Model MAC
-------------------------------------------------------
vnet1 bridge br0 virtio 52:54:00:93:bf:07
vnet2 bridge virbr0 rtl8139 52:54:00:29:ed:8b
[root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test.xml
进入test虚拟机，查看网卡信息，命令如下：
[root@kvm ~]# virsh console test
[root@localhost ~]# ifconfig
ens10: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.122.8 netmask 255.255.255.0 broadcast 192.168.122.255
inet6 fe80::5054:ff:fe29:ed8b prefixlen 64 scopeid 0x20<link>
ether 52:54:00:29:ed:8b txqueuelen 1000 (Ethernet)
RX packets 5186 bytes 7413267 (7.0 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1480 bytes 84889 (82.8 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens11: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.16.129 netmask 255.255.255.0 broadcast 192.168.16.255
inet6 fe80::5054:ff:fe15:abbd prefixlen 64 scopeid 0x20<link>
ether 52:54:00:15:ab:bd txqueuelen 1000 (Ethernet)
RX packets 13 bytes 1328 (1.2 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 16 bytes 1668 (1.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 52:54:00:93:bf:07 txqueuelen 1000 (Ethernet)
RX packets 55 bytes 8520 (8.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
7.迁移虚拟机
首先关闭虚拟机，命令如下：
[root@kvm ~]# virsh shutdown test
Domain test is being shutdown
查看虚拟机磁盘所在目录，命令如下：
[root@kvm ~]# virsh domblklist test
Target Source
------------------------------------------------
vda /kvm_data/test.img
vdb /kvm_data/test_2.img
hda -
[root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test03.xml
//如果是远程机器，需要把该配置文件拷贝到远程机器上
[root@kvm ~]# rsync -av /kvm_data/test.img /kvm_data/test03.img
//-bash: rsync: command not found则yum install -y rsync
//如果是迁移到远程，则需要把该磁盘文件拷贝到远程机器上
sending incremental file list
test.img
sent 10,742,006,844 bytes received 35 bytes 60,179,310.25 bytes/sec
total size is 10,739,384,832 speedup is 1.00
因为是迁移到本机，配置文件用的是test子机的配置，不改会有冲突，所以需要修改该文件，如果是远程机器不用修改：
[root@kvm ~]# vi /etc/libvirt/qemu/test03.xml
<name>test03</name>
//修改domname:
//修改uuid（随便改一下数字，位数不要变）
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/kvm_data/test03.img'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
//修改磁盘路径
定义新虚拟机，命令如下：
[root@kvm ~]# virsh define /etc/libvirt/qemu/test03.xml
Domain test03 defined from /etc/libvirt/qemu/test03.xml
查看虚拟机列表，会发现新迁移的虚拟机test03：
[root@kvm ~]# virsh list --all
Id Name State
----------------------------------------------------
6 test02 running
- test shut off
- test03 shut off
