说明：
Kernel-based Virtual Machine的简称，是一个开源的系统虚拟化 模块，自Linux 2.6.20之后集成在Linux的各个主要发行版本中。它使用Linux自身的调度器进行管理，所以相对于Xen ，其核心源码很少。KVM已成为学术界的主流VMM 之一。
KVM的虚拟化需要硬件支持（如[Intel VT](https://baike.baidu.com/item/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。
中文名：KVM虚拟机
解 释：一个开源的系统虚拟化 模块
应 用：Linux自身的调度器进行管理
价 值：成为学术界的主流VMM之一
本文系统环境：Centos 7.0
安装KVM
使用egrep ‘(vmx|svm)’ /proc/cpuinfo 命令验证CPU是否支持KVM；如果结果中有vmx（Intel）或svm(AMD)字样，就说明CPU的支持的。
1 2 3 4 5 6 [root@localhost.localdomain:/root ] flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm ida arat epb dtherm tpr_shadow vnmi ept vpid tsc_adjust flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm ida arat epb dtherm tpr_shadow vnmi ept vpid tsc_adjust flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm ida arat epb dtherm tpr_shadow vnmi ept vpid tsc_adjust flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes hypervisor lahf_lm ida arat epb dtherm tpr_shadow vnmi ept vpid tsc_adjust
关闭SELinux，将 /etc/sysconfig/selinux 中的 SELinux=enforcing 修改为 SELinux=disabled
1 sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
因为我是刚安装好的CentOS，所以为了下面方便点，先把一些必要的工具安装下
1 yum install epel-release net-tools vim unzip zip wget -y
1 yum install qemu-kvm libvirt virt-install bridge-utils openssl -y
使用lsmod | grep kvm命令验证安装结果，下图说明已经成功安装了
1 2 3 4 [root@localhost.localdomain:/root ] kvm_intel 138567 0 kvm 441119 1 kvm_intel
1 2 3 4 5 [root@localhost.localdomain:/root ] [root@localhost.localdomain:/root ]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 [root@localhost.localdomain:/root ] ● libvirtd.service - Virtualization daemon Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled) Active: active (running) since Mon 2020-04-13 21:50:59 CST; 54s ago Docs: man:libvirtd(8) https://libvirt.org Main PID: 14134 (libvirtd) CGroup: /system.slice/libvirtd.service ├─14134 /usr/sbin/libvirtd ├─14244 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper └─14245 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper Apr 13 21 :50:59 localhost.localdomain libvirtd[14134]: 2020-04-13 13:50:59.333 +0000: 14150: warning : virQEMUCapsInit:955 : Failed to get host CPU cache info Apr 13 21 :50:59 localhost.localdomain libvirtd[14134]: 2020-04-13 13:50:59.694 +0000: 14150: warning : virLXCDriverCapsInit:82 : Failed to get host CPU cache info Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: started, version 2.66 cachesize 150 Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: compile time options: IPv6 GNU-getopt DBus no -i18n IDN DHCP DHCPv6 no -Lua TFTP no -conntrack ipset auth Apr 13 21 :51:00 localhost.localdomain dnsmasq-dhcp[14244]: DHCP, IP range 192.168 .122 .2 -- 192.168 .122 .254 , lease time 1h Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: reading /etc/resolv.conf Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: using nameserver 192.168 .0 .1 Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: read /etc/hosts - 2 addresses Apr 13 21 :51:00 localhost.localdomain dnsmasq[14244]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses Apr 13 21 :51:00 localhost.localdomain dnsmasq-dhcp[14244]: read /var/lib/libvirt/dnsmasq/default.hostsfile
在/etc/sysconfig/network-scripts/目录下创建ifcfg-br0文件，内容如下
1 2 3 4 5 6 7 8 9 [root@localhost.localdomain:/etc/sysconfig/network-scripts ] BOOTPROTO=static DEVICE=br0 TYPE=Bridge NM_CONTROLLED=no IPADDR=192.168.0.145 NETMASK=255.255.255.0 GATEWAY=192.168.0.1
修改原网卡配置文件，内容如下（修改之前最好先备份一下）
1 2 3 4 5 6 7 [root@localhost.localdomain:/etc/sysconfig/network-scripts ] BOOTPROTO=none DEVICE=eno16777736 NM_CONTROLLED=no ONBOOT=yes BRIDGE=br0
重启网络服务,使用 ifconfig 验证操作结果,多了一块网卡br0，能访问网络表示成功。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 [root@localhost.localdomain:/etc/sysconfig/network-scripts ] [root@localhost.localdomain:/etc/sysconfig/network-scripts ] br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168 .0 .145 netmask 255.255 .255 .0 broadcast 192.168 .0 .255 inet6 fe80::20c:29ff:fe4f:dcdb prefixlen 64 scopeid 0x20 <link> ether 00 :0c:29:4f:dc:db txqueuelen 0 (Ethernet) RX packets 30 bytes 4987 (4.8 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 28 bytes 4237 (4.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet6 fe80::20c:29ff:fe4f:dcdb prefixlen 64 scopeid 0x20 <link> ether 00 :0c:29:4f:dc:db txqueuelen 1000 (Ethernet) RX packets 53284 bytes 69822549 (66.5 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 36366 bytes 4039403 (3.8 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 8 bytes 688 (688.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 8 bytes 688 (688.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 192.168 .122 .1 netmask 255.255 .255 .0 broadcast 192.168 .122 .255 ether 52 :54:00:7c:b0:34 txqueuelen 0 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 7 bytes 1111 (1.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
安装虚拟机
创建创建虚拟机文件存放的目录和iso文件存放目录，准备操作系统安装镜像文件，在本文中将使用和宿主环境一样的CentOS7.0，把该文件放到 /data/kvm/iso 目录下
1 2 3 4 [root@localhost.localdomain:/etc/sysconfig/network-scripts ] [root@localhost.localdomain:/data/iso ]
使用 virt-install 创建虚拟机（virt-install命令详情请点击这里 ）
1 virt-install --vcpus=2 -n Centos7.0-1 -r 1024 --disk /data/kvm/kvm-mv/Centos7.0-1.img,format=qcow2,size=10 --network bridge=br0 --os-type=linux --os-variant=rhel7.0 --cdrom /data/kvm/iso/CentOS-7.0-1406-x86_64-DVD.iso --vnc --vncport=5910 --vnclisten=0.0.0.0
1 2 3 4 5 6 7 8 9 [root@localhost.localdomain:/data/kvm/iso ] WARNING Unable to connect to graphical console: virt-viewer not installed. Please install the 'virt-viewer' package. WARNING No console to launch for the guest, defaulting to --wait -1 Starting install... Allocating 'Centos7.0-1.img' | 10 GB 00 :00:00 Domain installation still in progress. Waiting for installation to complete.
1 2 3 4 5 6 [root@localhost.localdomain:/root ] success [root@localhost.localdomain:/root ] success
1 2 3 4 5 [root@localhost.localdomain:/data/kvm/iso ] Id Name State ---------------------------------------------------- 2 Centos7.0-1 running
创建windows虚拟机命令
1 virt-install --vcpus=2 -n windows_2012 -r 2048 --disk /data/kvm/windows2012.qcow2,format=qcow2,size=20 --network bridge=br0 --os-type=windows --os-variant=win2k12r2 --cdrom /data/iso/cn_windows_server_2012_r2_x64_dvd_2707961.iso --disk path=/data/iso/virtio-win-1.7.4.iso,device=floppy --vnc --vncport=5910 --vnclisten=0.0.0.0
简单配置KVM虚拟机
1 2 3 4 5 6 7 8 9 10 [root@localhost.localdomain:/data/kvm/iso ] GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL="console serial" GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1" GRUB_CMDLINE_LINUX="rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb" GRUB_CMDLINE_LINUX_DEFAULT="console=tty1 console=ttyS0,115200" GRUB_DISABLE_RECOVERY="true"
运行grub2-mkconfig -o /boot/grub2/grub.cfg 之后重启虚拟机 reboot
1 2 3 4 5 6 7 8 9 10 [root@localhost.localdomain:/data/kvm/iso ] Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img Warning: Please don't use old title `CentOS Linux, with Linux 3.10 .0 -123. el7.x86_64' for GRUB_DEFAULT, use `Advanced options for CentOS Linux>CentOS Linux, with Linux 3.10 .0 -123. el7.x86_64' (for versions before 2.00 ) or `gnulinux-advanced-ccd3b657-a799-4562-86ed-cee7a3eded92>gnulinux-3.10.0-123.el7.x86_64-advanced-ccd3b657-a799-4562-86ed-cee7a3eded92' (for 2.00 or later) Found linux image: /boot/vmlinuz-0-rescue-bf745f5a0bdc47c99aaf11abcf6934f3 Found initrd image: /boot/initramfs-0-rescue-bf745f5a0bdc47c99aaf11abcf6934f3.img done [root@localhost default ]
在宿主机上进入虚拟机控制台，想退出时使用 Ctrl 键+ ] （左方括号）键退出。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 [root@localhost.localdomain:/data/kvm/iso ] Id Name State ---------------------------------------------------- 2 Centos7.0-1 running [root@localhost.localdomain:/data/kvm/iso ] Connected to domain Centos7.0-1 Escape character is ^] CentOS Linux 7 (Core) Kernel 3.10 .0 -123. el7.x86_64 on an x86_64 localhost login:
迁移虚拟机
虚拟机建好后，最大的好处就是任由我们折腾，而不用担心重装系统的麻烦。所以一定要知道虚拟机怎么复制迁移，这里有两种情况，一种是本机上镜像复制，另一种是将本机镜像迁移到其他服务器上 。
本机复制
1 2 3 4 5 6 7 8 9 [root@localhost.localdomain:/data/kvm/iso ] Id Name State ---------------------------------------------------- 2 Centos7.0-1 running [root@localhost.localdomain:/data/kvm/iso ] Domain Centos7.0-1 is being shutdown
使用 virt-clone 克隆think8848-kvmbase为新的虚拟机
1 2 3 4 5 6 [root@localhost.localdomain:/data/kvm/iso ] WARNING Setting the graphics device port to autoport, in order to avoid conflicting. Allocating 'Centos7.0-1.bak.img' | 10 GB 00 :00:05 Clone 'Centos7.0-1.bak' created successfully.
1 2 3 4 5 6 [root@localhost.localdomain:/data/kvm/iso ] Id Name State ---------------------------------------------------- - Centos7.0-1 shut off - Centos7.0-1.bak shut off
开启Centos7.0-1.bak，然后修改IP地址、主机名等（步骤略过）这里就克隆完成了
将虚拟机镜像迁移到其他服务器上
1 2 3 [root@localhost.localdomain:/data/kvm/iso ] Domain Centos7.0-1.bak is being shutdown
先将虚拟机的配置文件和镜像文件传到目标服务器上相应的位置（具体看目标服务器虚拟机配置文件和镜像文件存放位置。）
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 [root@localhost.localdomain:/etc/libvirt/qemu ] [root@localhost.localdomain:/etc/libvirt/qemu ] The authenticity of host '192.168.0.169 (192.168.0.169)' can't be established. ECDSA key fingerprint is fa:15:d8:74:b1:46:44:2a:5b:9a:67:31:d6:68:0d:8f. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.0.169' (ECDSA) to the list of known hosts. root@192.168.0.169's password: Centos7.0-1.bak.xml 100 % 4102 4. 0KB/s 00 :00 [root@localhost.localdomain:/etc/libvirt/qemu ] [root@localhost.localdomain:/data/kvm/kvm-mv ] root@192.168.0.169's password: Centos7.0-1.bak.img 100 % 1057MB 39. 2MB/s 00 :27
编辑Centos7.0-1.bak.xml 更改虚拟机镜像文件.img的路径，然后把UUID换为新的(直接使用这个 在线工具生成吧)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 [root@localhost.localdomain:/etc/libvirt/qemu ] <!-- WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE OVERWRITTEN AND LOST. Changes to this xml configuration should be made using: virsh edit Centos7.0-1.bak or other application using the libvirt API. --> <domain type='kvm'> <name>Centos7.0-1.bak</name> <uuid>fc7d1816-ceaf-40c5-947a-b293d4d734ef</uuid> <===重新生成的uuid <memory unit='KiB'>1048576</memory> <currentMemory unit='KiB'>1048576</currentMemory> <vcpu placement='static'>2</vcpu> <os> <type arch='x86_64' machine='pc-i440fx-rhel7.0.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> </features> <cpu mode='custom' match='exact' check='partial'> <model fallback='allow'>Westmere</model> </cpu> <clock offset='utc'> <timer name='rtc' tickpolicy='catchup'/> <timer name='pit' tickpolicy='delay'/> <timer name='hpet' present='no'/> </clock> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <pm> <suspend-to-mem enabled='no'/> <suspend-to-disk enabled='no'/> </pm> <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/data/kvm/Centos7.0-1.bak.img'/> <===镜像路径 <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 [root@localhost.localdomain:/etc/libvirt/qemu ] Domain Centos7.0-1.bak defined from /etc/libvirt/qemu/Centos7.0-1.bak.xml [root@localhost.localdomain:/etc/libvirt/qemu ] Id Name State ---------------------------------------------------- - Centos7.0-1.bak shut off [root@localhost.localdomain:/etc/libvirt/qemu ] Domain Centos7.0-1.bak started [root@localhost.localdomain:/etc/libvirt/qemu ] Connected to domain Centos7.0-1.bak Escape character is ^] [root@localhost ~ ]
1 2 3 <graphics type='vnc' port='10000' autoport='no' listen='0.0.0.0'> <listen type='address' address='0.0.0.0'/> </graphics
KVM管理
请产考kvm常用命令
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