kvm：日常使用
常用命令
创建新镜像：qemu-img create -f qcow2 /var/lib/libvirt/images/$1.img 100G
创建新镜像：qemu-img create -f qcow2 -o preallocation=metadata /var/lib/libvirt/images/$1.img 200G （真实大小）
创建虚拟机：virt-install --name $1 --ram 4096 --vcpus=2 --disk path=/var/lib/libvirt/images/$1.img,size=100 --accelerate --cdrom /data/iso/ubuntu-14.04.5-server-amd64.iso --graphics vnc,listen=0.0.0.0
基于老镜像创建镜像：qemu-img create -f qcow2 -b /var/lib/libvirt/images/old.img /var/lib/libvirt/images/new.img
启动虚拟机：virsh start vmname
关闭虚拟机：virsh shutdown vmname
强制关闭虚拟机：virsh destroy vmname
删除虚拟机：virsh undefine vmname
查看虚拟机网卡：virsh domiflist vmname
添加网卡：virsh attach-interface vmname --type bridge --source br1 --config
删除网卡：virsh detach-interface vmname --type bridge --mac 52:54:00:14:86:cf
克隆虚拟机：virt-clone -o old_vmname -n new_vmname -f /var/lib/libvirt/images/new_vmname.img
创建快照：virsh snapshot-create-as vmname snapshot_name
查看虚拟机快照：virsh snapshot-list vmname
回滚快照：virsh snapshot-revert --domain vmname snapshot_name
删除快照：virsh snapshot-delete vmname snapshot_name
根据配置文件起虚拟机： virsh define /etc/libvirt/qemu/INIT-CASSANDRA-01.xml
virsh edit vmname 动态修改kvm配置文件
添加磁盘：
方法一：virsh attach-disk $kvmname $镜像位置 vda --subdriver qcow2 --config --live
方法二：
1，创建磁盘：
qemu-img create -f qcow2 /data/vm/huge.img 500G
2，编写一个xml文件（disk.xml）：
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source file='/data/vm/huge.img'/>
<target dev='vdb' bus='virtio'/>
</disk>
3，添加磁盘：
virsh attach-device --persistent vm-name disk.xml
安装新机器
qemu-img create -f qcow2 /var/lib/libvirt/images/$1.img 100G
virt-install --name $1 --ram 4096 --vcpus=2 --disk path=/var/lib/libvirt/images/$1.img,size=100 --accelerate --cdrom /data/iso/ubuntu-14.04.5-server-amd64.iso --graphics vnc,listen=0.0.0.0
virsh domiflist vsftp #查看vsftp虚拟机的网卡信息
virsh attach-interface vsftp --type bridge --source br1 --config #创建vsftp另一块网卡（注意网桥是两个不一样的）
virsh detach-interface vsftp --type bridge --mac 52:54:00:14:86:cf #删除网卡
ps -ef|grep $虚拟机名称 #查看vnc
vnc连接，添加一块虚拟机网卡
虚机网卡配置
vim /etc/network/interfaces
ubuntu网卡配置：
root@ubuntu:/etc# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
auto ens3
iface ens3 inet static
address 192.168.0.90
netmask 255.255.255.0
gateway 192.168.0.254
dns-nameservers 192.168.0.25
dns-search redmine
auto ens6
iface ens6 inet static
address 10.0.18.90
netmask 255.255.252.0
# gateway 10.0.16.1
network 10.0.16.0
broadcast 10.0.19.255
centos网卡配置
[root@kvm3 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_FAILURE_FATAL=no
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=192.168.0.53
NETMASK=255.255.255.0
[root@kvm3 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth1
rc.local添加命令
route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.0.16.1
报错
是因为配置文件中的os部分系统信息不正确导致，可以先virsh-install一台虚拟机，将os部分拷贝即可
vmname.xml
1 <domain type='kvm'> ##描述hypervisor 2 <name>centos7.0</name> ##定义虚拟机整体信息 3 <uuid>c2d264d3-5c61-4d2e-8678-b28673c1f64b</uuid> 4 <memory unit='KiB'>1048576</memory> 5 <currentMemory unit='KiB'>1048576</currentMemory> 6 <vcpu placement='static'>1</vcpu> 7 <os> ##系统信息 8 <type arch='x86_64' machine='pc-i440fx-rhel7.0.0'>hvm</type> 9 <boot dev='hd'/> ##开机从哪里启动 10 </os> 11 <features> ##硬件资源特性 12 <acpi/> 13 <apic/> 14 </features> 15 <cpu mode='custom' match='exact'> 16 <model fallback='allow'>Haswell-noTSX</model> 17 </cpu> 18 <clock offset='utc'> 19 <timer name='rtc' tickpolicy='catchup'/> 20 <timer name='pit' tickpolicy='delay'/> 21 <timer name='hpet' present='no'/> 22 </clock> 23 <on_poweroff>destroy</on_poweroff> ##突发事件处理 24 <on_reboot>restart</on_reboot> 25 <suspend-to-mem enabled='no'/> 26 <suspend-to-disk enabled='no'/> 27 </pm> 28 <devices> ##外设资源 29 <emulator>/usr/libexec/qemu-kvm</emulator> 30 <disk type='file' device='disk'> ##描述虚拟磁盘image 31 <driver name='qemu' type='qcow2'/> 32 <source file='/var/lib/libvirt/images/centos7.0.qcow2'/> 33 <target dev='vda' bus='virtio'/> 34 <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> 35 </disk> 36 <controller type='usb' index='0' model='ich9-ehci1'> 37 <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x7'/> 38 </controller> 39 <controller type='usb' index='0' model='ich9-uhci1'> 40 <master startport='0'/> 41 </controller> 42 <controller type='usb' index='0' model='ich9-uhci2'> 43 <master startport='2'/> 44 <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x1'/> 45 </controller> 46 <controller type='usb' index='0' model='ich9-uhci3'> 47 <master startport='4'/> 48 <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x2'/> 49 <controller type='virtio-serial' index='0'> 50 <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> 51 </controller> 52 <interface type='bridge'> ##虚拟网络，基于网桥 53 <mac address='52:54:00:6a:1e:54'/> 54 <source bridge='br0'/> 55 <model type='virtio'/> 56 <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> 57 </interface> 58 <serial type='pty'> ##串口信息可以不用更改 59 <target port='0'/> 60 </serial> 61 <console type='pty'> 62 <target type='serial' port='0'/> 63 </console> 64 <channel type='unix'> 65 <target type='virtio' name='org.qemu.guest_agent.0'/> 66 <address type='virtio-serial' controller='0' bus='0' port='1'/> 67 </channel> 68 <channel type='spicevmc'> 69 <target type='virtio' name='com.redhat.spice.0'/> 70 <address type='virtio-serial' controller='0' bus='0' port='2'/> 71 </channel> 72 <input type='tablet' bus='usb'/> 73 <input type='mouse' bus='ps2'/> 74 <input type='keyboard' bus='ps2'/> 75 <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/> 76 <sound model='ich6'> ##从此往下的内容可以不用更改 77 <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> 78 </sound> 79 <video> 80 <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1'/> 81 <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> 82 </video> 83 <redirdev bus='usb' type='spicevmc'> 84 </redirdev> 85 <redirdev bus='usb' type='spicevmc'> 86 </redirdev> 87 <memballoon model='virtio'> 88 <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/> 89 </memballoon> 90 </devices> 91 </domain>
第一行定义了虚拟机的名字。libvirt可以通过虚拟机的名字对虚拟机进行管理。在同一台物理机上，虚拟机的名字必须要保证唯一的。如果存在重名的情况，添加和创建虚拟机时，会失败。
第二行定义的虚拟机的UUID。在同一台物理机上，UUID值也必须是唯一的，否则会出现冲突。
第三四行描述虚拟机的内存信息，通常以KB为单位。
第五行指明了分配的虚拟CPU的个数。
