一虱咧、KVM虛擬化介紹
1宏多、虛擬化
指通過(guò)虛擬化技術(shù)將一臺(tái)計(jì)算機(jī)虛擬為多臺(tái)邏輯計(jì)算機(jī)瑞凑。在一臺(tái)計(jì)算機(jī)上同時(shí)運(yùn)行多個(gè)邏輯計(jì)算機(jī)，每個(gè)邏輯計(jì)算機(jī)可運(yùn)行不同的操作系統(tǒng)陡叠，并且應(yīng)用程序都可以在相互獨(dú)立的空間內(nèi)運(yùn)行而互相不影響玩郊，從而顯著提高計(jì)算機(jī)的工作效率。
2匾竿、kvm
KVM（Kernel-based Virtual Machine）基于內(nèi)核的虛擬機(jī)
虛擬化使用軟件的方法重新定義劃分 IT 資源瓦宜，可以實(shí)現(xiàn) IT 資源的動(dòng)態(tài)分配、靈活調(diào)度岭妖、跨域共享临庇，提高 IT 資源利用率，使 IT 資源能夠真正成為社會(huì)基礎(chǔ)設(shè)施昵慌，服務(wù)于各行各業(yè)中靈活多變的應(yīng)用需求假夺。
KVM 是基于虛擬化擴(kuò)展（Intel VT 或者 AMD-V）的 X86 硬件的開(kāi)源的 Linux 原生的全虛擬化解決方案，KVM 中斋攀，虛擬機(jī)被實(shí)現(xiàn)為常規(guī)的 Linux 進(jìn)程已卷，由標(biāo)準(zhǔn) Linux 調(diào)度程序進(jìn)行調(diào)度；虛機(jī)的每個(gè)虛擬 CPU 被實(shí)現(xiàn)為一個(gè)常規(guī)的 Linux 線程淳蔼。這使得 KMV 能夠使用 Linux 內(nèi)核的已有功能侧蘸。
KVM使用QEMU進(jìn)行硬件的模擬裁眯，使用libvirt作為管理接口
二、KVM安裝虛擬機(jī)
1讳癌、軟件及服務(wù)
virt-install 安裝虛擬機(jī)軟件
virt-manager 圖形化界面管理
libvirt* 為虛擬化做統(tǒng)一接口
2穿稳、安裝過(guò)程
實(shí)驗(yàn)環(huán)境
server 192.168.200.12
[root@server ~]# egrep "svm|vmx" /proc/cpuinfo
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht 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 ssbd ibrs ibpb stibp tpr_shadow vnmi ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec arat spec_ctrl intel_stibp flush_l1d arch_capabilities
[root@server ~]# lsmod | grep kvm
kvm_intel 183621 0
kvm 586948 1 kvm_intel
irqbypass 13503 1 kvm
檢查cpu對(duì)虛擬化的是否支持，內(nèi)核是否加載虛擬化模塊
如果沒(méi)有晌坤，在虛擬機(jī)設(shè)置處理器中打開(kāi)虛擬化引擎image.png
[root@server ~]# yum -y install virt-install virt-manager libvirt*
[root@server ~]# systemctl start libvirtd
[root@server ~]# systemctl enable libvirtd
[root@server ~]# systemctl status libvirtd
● libvirtd.service - Virtualization daemon
Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2020-02-07 17:28:24 CST; 10min ago
Docs: man:libvirtd(8)
https://libvirt.org
Main PID: 23156 (libvirtd)
CGroup: /system.slice/libvirtd.service
├─10291 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/...
├─10292 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/...
└─23156 /usr/sbin/libvirtd
Feb 07 17:28:24 server systemd[1]: Starting Virtualization daemon...
Feb 07 17:28:24 server systemd[1]: Started Virtualization daemon.
Feb 07 17:28:25 server dnsmasq[10291]: read /etc/hosts - 2 addresses
Feb 07 17:28:25 server dnsmasq[10291]: read /var/lib/libvirt/dnsmasq/defa...s
Feb 07 17:28:25 server dnsmasq-dhcp[10291]: read /var/lib/libvirt/dnsmasq...e
Hint: Some lines were ellipsized, use -l to show in full.
安裝軟件逢艘，打開(kāi)服務(wù)
[root@server ~]# qemu-img create -f qcow2 /var/lib/libvirt/images/test1.qcow2 5G
Formatting '/var/lib/libvirt/images/test1.qcow2', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536 lazy_refcounts=off
[root@server images]# rz
rz waiting to receive.
zmodem trl+C ?
100% 940032 KB 23500 KB/s 00:00:40 0 Errors-1810.iso...
[root@server images]# ls
CentOS-7-x86_64-Minimal-1810.iso test1.qcow2
[root@server images]# virt-install \
> --virt-type kvm \
> --name test1 \
> --vcpus=1 \
> --ram 1024 \
> --cdrom=/var/lib/libvirt/images/CentOS-7-x86_64-Minimal-1810.iso \
> --disk path=/var/lib/libvirt/images/test1.qcow2 \
> --network network=default \
> --graphics vnc,listen=0.0.0.0,port=5901
創(chuàng)建磁盤，上傳鏡像骤菠，創(chuàng)建虛擬機(jī)
virt-install
--virt-type kvm 虛擬化類型kvm
--name test1 虛擬機(jī)名字
--vcpus=1 虛擬機(jī)cpu
--ram 1024 虛擬機(jī)內(nèi)存
--cdrom=/var/lib/libvirt/images/CentOS-7-x86_64-Minimal-1810.iso 虛擬機(jī)鏡像路徑
--disk path=/var/lib/libvirt/images/test1.qcow2 虛擬機(jī)磁盤路徑
--network network=default 虛擬機(jī)網(wǎng)絡(luò)它改，默認(rèn)為NAT
--graphics vnc,listen=0.0.0.0,port=5901 vnc管理監(jiān)聽(tīng)地址與端口
三、KVM管理虛擬機(jī)
1商乎、libvirtd
Libvirtd是目前使用最廣泛的對(duì)kvm虛擬機(jī)進(jìn)行管理的工具和api央拖。Libvirtd是一個(gè)Domain進(jìn)程可以被本地virsh調(diào)用，也可以被遠(yuǎn)端的virsh調(diào)用截亦，libvirtd調(diào)用kvm-qemu控制虛擬機(jī)爬泥。
libvirtd由幾個(gè)不同的部分組成，其中包括應(yīng)用程序編程接口（API）庫(kù)崩瓤，一個(gè)守護(hù)進(jìn)程（libvirtd）和一個(gè)默認(rèn)的命令行工具(virsh)袍啡，libvirtd守護(hù)進(jìn)程負(fù)責(zé)對(duì)虛擬機(jī)的管理，因此要確保這個(gè)進(jìn)程的運(yùn)行却桶。
2境输、virt-manager管理
virt-manager是一套強(qiáng)大的虛擬機(jī)桌面管理工具，提供了對(duì)虛擬機(jī)的開(kāi)機(jī)颖系，掛起嗅剖，重啟，網(wǎng)絡(luò)嘁扼，內(nèi)存信粮，CPU，磁盤趁啸，遷移等
[root@server images]# virt-manager
image.png
3强缘、virsh管理
virsh是由libvirt提供的管理工具，配合虛擬機(jī)xml文件基本可以完成對(duì)虛擬機(jī)的所有操作
利用virsh實(shí)現(xiàn)跨主機(jī)管理
實(shí)驗(yàn)環(huán)境 192.168.200.13
[root@localhost ~]# vi /etc/libvirt/libvirt.conf
uri_aliases = [
"kvm=qemu+ssh://192.168.200.12/system",
]
[root@localhost ~]# ssh-keygen
[root@localhost ~]# ssh-copy-id root@192.168.200.12
[root@localhost ~]# virsh -c kvm
Welcome to virsh, the virtualization interactive terminal.
Type: 'help' for help with commands
'quit' to quit
virsh #
4不傅、vnc管理
VNC (Virtual Network Console)是虛擬網(wǎng)絡(luò)控制臺(tái)的縮寫旅掂。它是一款優(yōu)秀的遠(yuǎn)程控制工具軟件，由著名的 AT&T的歐洲研究實(shí)驗(yàn)室開(kāi)發(fā)的访娶。VNC 是在基于UNIX和Linux操作系統(tǒng)的免費(fèi)的開(kāi)源軟件商虐，遠(yuǎn)程控制能力強(qiáng)大，高效實(shí)用，其性能可以和Windows和MAC中的任何遠(yuǎn)程控制軟件媲美秘车。
[root@server images]# vncviewer :5901
5典勇、console管理
通過(guò)console口在宿主機(jī)直接接管虛擬機(jī)
[root@server ~]# vi /etc/default/grub
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb q
uiet console=ttyS0"
[root@server ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
[root@server ~]# reboot
[root@server ~]# virsh start test1
[root@server ~]# virsh console test1
6、xml文件
每一個(gè)虛擬機(jī)都有一個(gè)以.xml結(jié)尾定義文件鲫尊，其中定義了所有虛擬機(jī)的虛擬化配置痴柔，默認(rèn)路徑為/etc/libvirt/qemu/xxx.xml
四、KVM CPU
1疫向、基本概念
- 對(duì)于虛擬化而言，一個(gè)vm在宿主機(jī)上就是一個(gè)進(jìn)程
- 而虛擬機(jī)的cpu就是這個(gè)進(jìn)程下的一個(gè)線程
2豪嚎、定義CPU
<vcpu placement='static'>1</vcpu> 最大cpu為1搔驼，當(dāng)前cpu為1
<vcpu placement='static' current='1'>3</vcpu> 最大cpu為3，當(dāng)前cpu為1
3侈询、CPU增加
將虛擬機(jī)一個(gè)cpu增加至三個(gè)
[root@server ~]# vim /etc/libvirt/qemu/test1.xml
<vcpu placement='static' current='3'>4</vcpu>
[root@server ~]# virsh destroy test1
Domain test1 destroyed
[root@server ~]# systemctl restart libvirtd
[root@server ~]# virsh start test1
Domain test1 started
驗(yàn)證
[root@server ~]# ssh root@192.168.122.131 "cat /proc/cpuinfo | grep processor"
root@192.168.122.131's password:
processor : 0
processor : 1
processor : 2
4舌涨、CPU模式
- 默認(rèn) 默認(rèn)為在虛擬機(jī)性能最好的cpu
- host-passthrougt 具有和宿主機(jī)相同的cpu，為了實(shí)現(xiàn)虛擬化嵌套
- host-model 和宿主機(jī)最接近的cpu
五扔字、KVM MEM
1囊嘉、基礎(chǔ)概念
host physical memory 是服務(wù)器的cpu，最真實(shí)的cpu
guest physical memory 是宿主機(jī)的cpu
guest virtual memory 是虛擬機(jī)的cpu
2革为、定義MEN
<memory unit='KiB'>4194304</memory> 最大cpu為4G
<currentMemory unit='KiB'>1048576</currentMemory> 當(dāng)前cpu為1G
3扭粱、balloon
KVM的內(nèi)存氣球技術(shù)使得可以在虛擬機(jī)中按照需要調(diào)整的內(nèi)存大小，提升內(nèi)存的利用率震檩。使用的時(shí)候琢蛤，默認(rèn)情況是需要安裝virt balloon的驅(qū)動(dòng)，內(nèi)核開(kāi)啟CONFIG_VIRTIO_BALLOON抛虏。CentOS7默認(rèn)已經(jīng)開(kāi)啟了此選項(xiàng)博其，并且也安裝了virtballoon驅(qū)動(dòng)。
查看當(dāng)前氣球大小
[root@server ~]# virsh qemu-monitor-command test1 --hmp --cmd info balloon
balloon: actual=1024
增加氣球容量
virsh qemu-monitor-command test1 --hmp --cmd balloon 2048
驗(yàn)證
[root@server ~]# ssh root@192.168.122.131 "free -m"
root@192.168.122.131's password:
total used free shared buff/cache available
Mem: 1741 122 1424 8 194 1385
Swap: 511 0 511
4迂猴、內(nèi)存增加
將1G內(nèi)存增加至3G
[root@server ~]# vim /etc/libvirt/qemu/test1.xml
<memory unit='KiB'>4194304</memory>
<currentMemory unit='KiB'>3145728</currentMemory>
[root@server ~]# virsh destroy test1
Domain test1 destroyed
[root@server ~]# systemctl restart libvirtd
[root@server ~]# virsh start test1
Domain test1 started
驗(yàn)證
[root@server ~]# ssh root@192.168.122.131 "free -m"
root@192.168.122.131's password:
total used free shared buff/cache available
Mem: 2765 115 2456 8 192 2417
Swap: 511 0 511
5慕淡、內(nèi)存超分配
- 內(nèi)存置換
- 內(nèi)存共享
- 內(nèi)存氣泡
六、KVM 存儲(chǔ)
1沸毁、概念
- 存儲(chǔ)池：為vm提供磁盤的存儲(chǔ)空間
- 存儲(chǔ)卷：虛擬機(jī)磁盤
2峰髓、類型
- 文件系統(tǒng)
-
塊設(shè)備
image.png
3、創(chuàng)建池（文件系統(tǒng)）
根據(jù)模板文件修改池定義文件以清，創(chuàng)建池
[root@server ~]# virsh pool-list
Name State Autostart
-------------------------------------------11
images active yes
[root@server ~]# virsh pool-dumpxml images > /root/pool_xml
[root@server ~]# vim pool_xml
<pool type='dir'>
<name>pool</name>
<target>
<path>/pool/</path>
<permissions>
<mode>0711</mode>
<owner>0</owner>
<group>0</group>
<label>system_u:object_r:virt_image_t:s0</label>
</permissions>
</target>
</pool>
[root@server ~]# mkdir /pool/
[root@server ~]# virsh pool-define /root/pool_xml
Pool pool defined from /root/pool_xml
[root@server ~]# virsh pool-list --all
Name State Autostart
-------------------------------------------
images active yes
pool inactive no
[root@server ~]# virsh pool-start pool
Pool pool started
[root@server ~]# virsh pool-autostart pool
Pool pool marked as autostarted
[root@server ~]# virsh pool-list
Name State Autostart
-------------------------------------------
images active yes
pool active yes
驗(yàn)證
[root@server pool]# qemu-img create -f qcow2 local.qcow2 2G
Formatting 'local.qcow2', fmt=qcow2 size=2147483648 encryption=off cluster_size=65536 lazy_refcounts=off
[root@server pool]# virsh attach-disk test1 /pool/local.qcow2 vdb --subdriver=qcow2
Disk attached successfully
[root@server ~]# virsh domblklist test1
Target Source
------------------------------------------------
vda /var/lib/libvirt/images/test1.qcow2
vdb /pool/local.qcow2
virsh detach-disk test1 vdc 移除磁盤
virsh detach-disk test1 vdc --config 移除磁盤配置文件
4儿普、后端存儲(chǔ)和前端存儲(chǔ)
這里的后端存儲(chǔ)并不是塊設(shè)備或者文件系統(tǒng)提供虛擬機(jī)持續(xù)化的存儲(chǔ)。而是依靠裝有系統(tǒng)的磁盤來(lái)創(chuàng)建虛擬機(jī)掷倔。這個(gè)虛擬機(jī)的磁盤文件被稱為前端存儲(chǔ)眉孩，裝有系統(tǒng)的磁盤被稱為后端存儲(chǔ)。前端存儲(chǔ)依靠后端存儲(chǔ)，相當(dāng)于創(chuàng)建了一個(gè)快照軟鏈接浪汪，在創(chuàng)建虛擬機(jī)的時(shí)候使用后端存儲(chǔ)做只讀文件巴柿。運(yùn)用這種方式可以很快的創(chuàng)建虛擬機(jī)。
[root@server images]# qemu-img create -f qcow2 -b test1.qcow2 vm1.qcow2
Formatting 'vm1.qcow2', fmt=qcow2 size=5368709120 backing_file='test1.qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
使用vm1.qcow2創(chuàng)建虛擬機(jī)相當(dāng)于鏈接快照死遭，完全依賴于test1.qcow2這個(gè)裝有系統(tǒng)的磁盤
5广恢，磁盤格式轉(zhuǎn)換
將qcow2的格式轉(zhuǎn)發(fā)為vmdk
[root@server images]# qemu-img create -f qcow2 test.qcow2 1G
Formatting 'test.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off
[root@server images]# qemu-img convert -O vmdk -f qcow2 test.qcow2 test.vmdk
檢查
[root@server images]# qemu-img info test.vmdk
image: test.vmdk
file format: vmdk
virtual size: 1.0G (1073741824 bytes)
disk size: 12K
cluster_size: 65536
Format specific information:
cid: 1293804866
parent cid: 4294967295
create type: monolithicSparse
extents:
[0]:
virtual size: 1073741824
filename: test.vmdk
cluster size: 65536
format:
[root@server images]# qemu-img check test.vmdk
No errors were found on the image.
七、kvm網(wǎng)絡(luò)
1呀潭、bridge
linux bridge
創(chuàng)建linuxbridge br0
[root@server ~]# cd /etc/sysconfig/network-scripts/
[root@server network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@server network-scripts]# vim ifcfg-br0
TYPE=Bridge
BOOTPROTO=none
NAME=br0
DEVICE=br0
ONBOOT=yes
IPADDR=192.168.200.12
NETMASK=255.255.255.0
GATEWAY=192.168.200.1
DNS1=114.114.114.114
[root@server network-scripts]# vim ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
NAME=ens33
BRIDGE=br0
[root@server ~]# systemctl restart network
[root@server ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29c90241 no ens33
virbr0 8000.525400ba4019 yes virbr0-nic
vnet0
驗(yàn)證
[root@server images]# vim boot
virt-install --virt-type kvm --name test2 --vcpus=1 --ram 1024 --cdrom=/var/lib/libvirt
/images/CentOS-7-x86_64-Minimal-1810.iso --disk path=/var/lib/libvirt/images/test2.qcow
2 --network bridge=br0 --graphics vnc,listen=0.0.0.0,port=5902
[root@server images]# qemu-img create -f qcow2 test2.qcow2 5G
Formatting 'test2.qcow2', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536 lazy_refcounts=off
[root@server images]# source boot
[root@server images]# virsh domiflist test2
Interface Type Source Model MAC
-------------------------------------------------------
vnet1 bridge br0 virtio 52:54:00:34:5d:62
[root@server images]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29c90241 no ens33
vnet1
virbr0 8000.525400ba4019 yes virbr0-nic
vnet0
openvswitch
創(chuàng)建openvswitch br1
[root@server ~]# yum -y install *openvswitch*
[root@server ~]# systemctl start openvswitch && systemctl enable openvswitch
Created symlink from /etc/systemd/system/multi-user.target.wants/openvswitch.service to /usr/lib/systemd/system/openvswitch.service.
[root@server ~]# cd /etc/sysconfig/network-scripts/
[root@server network-scripts]# cp ifcfg-ens33 ifcfg-br1
[root@server network-scripts]# vim ifcfg-br1
TYPE=OVSBridge
BOOTPROTO=none
NAME=br1
DEVICE=br1
ONBOOT=yes
DEVICETYPE=ovs
IPADDR=192.168.200.12
NETMASK=255.255.255.0
GATEWAY=192.168.200.1
DNS1=114.114.114.114
[root@server network-scripts]# vim ifcfg-ens33
TYPE=OVSPort
ONBOOT=yes
NAME=ens33
DEVICE=ens33
DEVICETYPE=ovs
OVS_BRIDGE=br1
[root@server ~]# systemctl restart network
[root@server ~]# ovs-vsctl show
0e9dac98-09c6-411c-b621-5e160e515b16
Bridge "br1"
Port "ens33"
Interface "ens33"
Port "br1"
Interface "br1"
type: internal
ovs_version: "2.5.0"
驗(yàn)證
[root@server ~]# vim /etc/libvirt/qemu/test2.xml
<interface type='bridge'>
<mac address='52:54:00:34:5d:62'/>
<source bridge='br1'/>
<virtualport type='openvswitch' />
<model type='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
[root@server ~]# virsh domiflist test2
Interface Type Source Model MAC
-------------------------------------------------------
vnet0 bridge br1 virtio 52:54:00:34:5d:62
[root@server ~]# ovs-vsctl show
0e9dac98-09c6-411c-b621-5e160e515b16
Bridge "br1"
Port "vnet0"
Interface "vnet0"
Port "ens33"
Interface "ens33"
Port "br1"
Interface "br1"
type: internal
ovs_version: "2.5.0"
2钉迷、NAT
在kvm中已經(jīng)默認(rèn)存在nat網(wǎng)絡(luò)
[root@server ~]# virsh net-list
Name State Autostart Persistent
----------------------------------------------------------
default active yes yes
[root@server ~]# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.525400ba4019 yes virbr0-nic
自定義nat網(wǎng)絡(luò) virbr1
[root@server ~]# virsh net-dumpxml default > /root/nat
[root@server ~]# vim nat
<network>
<name>nat</name>
<uuid>bc1b000b-7db8-4def-b272-5100bc5bfc88</uuid>
<forward mode='nat'>
<nat>
<port start='1024' end='65535'/>
</nat>
</forward>
<bridge name='virbr1' stp='on' delay='0'/>
<mac address='52:54:00:ba:40:19'/>
<ip address='192.168.188.1' netmask='255.255.255.0'>
<dhcp>
<range start='192.168.188.2' end='192.168.188.254'/>
</dhcp>
</ip>
</network>
[root@server ~]# virsh net-define /root/nat
Network nat defined from /root/nat
[root@server ~]# virsh net-list --all
Name State Autostart Persistent
----------------------------------------------------------
default active yes yes
nat inactive no yes
[root@server ~]# virsh net-start nat
Network nat started
[root@server ~]# virsh net-autostart nat
Network nat marked as autostarted
[root@server ~]# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.525400ba4019 yes virbr0-nic
virbr1 8000.525400ba4019 yes virbr1-nic
[root@server ~]# ifconfig virbr1
virbr1: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.188.1 netmask 255.255.255.0 broadcast 192.168.188.255
ether 52:54:00:ba:40:19 txqueuelen 1000 (Ethernet)
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
驗(yàn)證
[root@server images]# vim boot
virt-install --virt-type kvm --name test3 --vcpus=1 --ram 1024 --cdrom=/var/lib/libvi
rt/images/CentOS-7-x86_64-Minimal-1810.iso --disk path=/var/lib/libvirt/images/test3.
qcow2 --network network=nat --graphics vnc,listen=0.0.0.0,port=5903
[root@server images]# qemu-img create -f qcow2 test3.qcow2 5G
Formatting 'test3.qcow2', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536 lazy_refcounts=off
[root@server images]# source boot
[root@server ~]# virsh domiflist test2
Interface Type Source Model MAC
-------------------------------------------------------
vnet0 bridge br1 virtio 52:54:00:34:5d:62
[root@server ~]# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.525400ba4019 yes virbr0-nic
virbr1 8000.525400ba4019 yes virbr1-nic
vnet1