編譯和安裝

??1、（1）準備好libvirt-1.3.5安裝包，用MobaXterm工具將準備好的libvirt上傳到/usr/local/目錄下

?? ?（2）將libvirt-1.3.5.tar解壓到/usr/local/目錄下

???????? cd /usr/local/

??? ?????tar -zxf libvirt-1.3.5.tar.gz

??2、配置libvirt

??? (1)配置libvirt時，需運行libvirt目錄下的configure腳本文件。

??????? 進入libvirt解壓目錄下

??????? cd libvirt-1.3.5

??????? [root@localhost libvirt-1.3.5]#./configure

???????

??3、編譯libvirt

??? (1)配置。/configure成功后，在libvirt安裝目錄下執行“make”命令編譯。

????? ?cd libvirt-1.3.5

?????? [root@localhost libvirt-1.3.5]#make

??4、安裝libvirt，libvirt 安裝會默認安裝libvirtd和virsh等可執行程序。

???? (1)編譯完成后執行“make install”安裝libvirt

[root@localhost libvirt-1.3.5]# make install

???? (2)查看libvirtd位置命令：

[root@localhost libvirt-1.3.5]# which libvirtd

???????

???? (3)查看libvirtd版本號：libvirtd -version

?????

????? (4) 查看virsh位置命令：

?????????? [root@localhost libvirt-1.3.5]# which virsh

?????????

?????? (5)查看virsh版本號:

???????? [root@localhost libvirt-1.3.5]# virsh -version

????????

????? (6)查看libvirtd和virsh的頭文件和庫文件：

???????? [root@localhost libvirt-1.3.5]# ls /usr/local/include/libvirt

????????

??????? [root@localhost libvirt-1.3.5]# ls /usr/local/lib/libvirt*

???????

?? 5、查看已經安裝的libvirt

????? 查看libvirt是否啟動，實質是查看libvirt的libvirtd這個守護進程是否啟動。

??? ??(1) [root@localhost libvirt-1.3.5]# ps -le |grep libvirtd

????

????? (2)啟動libvirt

[root@localhost libvirt-1.3.5]# service?libvirtd?start

[root@localhost libvirt-1.3.5]# service?libvirtd?status

• libvirt的配置文件

??? 1、libvirt文件配置

（1）libvirt的配置文件一般在/etc/libvirt/目錄下

?????? [root@localhost ~]# cd /etc/libvirt

?????? [root@localhost libvirt]# ls

??? 2、libvirt中域的XML配置文件格式

?<domain type='kvm'>

???? <!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->

???? <name>libvirt</name>

?? ??<uuid>32b95fab-6d78-4e28-beca-2d3988ff8c8e</uuid>

??? ?<memory unit='KiB'>1048576</memory>

???? <currentMemory unit='KiB'>1048576</currentMemory>

???? <vcpu placement='static'>1</vcpu>

???? <os>

????????? <type arch='x86_64' machine='pc-1.2'>hvm</type>

????????? <boot dev='hd'/>

???????? ?<boot dev='cdrom'/>

???? </os>

???? <features>

???????? ?<acpi/>

????????? <apic/>

????????? <pae/>

???? </features>

???? ?<clock offset='utc'/>

? ????<on_poweroff>destroy</on_poweroff>

???? ?<on_reboot>restart</on_reboot>

???? ?<on_crash>restart</on_crash>

???? <devices>

??? ??<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->

??? ??<emulator>/usr/local/bin/qemu-system-x86_64</emulator>

??? ??<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->

??? ??<disk type='file' device='disk'>

??? ????<driver name='qemu' type='qcow2'/>

????? ??<source file='/tmp/ubuntu.img'/>

????? ??<target dev='hda' bus='ide'/>

????? ??<address type='drive' controller='0' buss='0' target='0' unit='0'/>

???? ?</disk>

??? ??<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->

???? ?<disk type='file' device='cdrom'>

??????? ?<driver name='qemu' type='raw'/>

???????? <source file='/tmp/ubuntu-18.04.5-desktop-amd64.iso'/>

??????? ?<target dev='hdc' bus='ide'/>

???????? <readonly/>

???? ?</disk>

? ????<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->

<controller type='usb' index='0'>

?? ??????<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>

????? </controller>

??? ??<controller type='ide' index='0'>

? ???????<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>

? ????</controller>

? ??????<interface type='bridge'>

???? ?????<mac address='52:54:00:78:f9:98'/>

???? ?????<source bridge='virbr0'/>

??? ??????<model type='virtio'/>

? ????????<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

???? ???</interface>

????????? <input type='mouse' bus='ps2'/>

????????? <graphics type='vnc' port='-1' autoprot='yes'/>

???????? ?<memballoon model='virtio'>

?????????? ?<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>

????? ????</memballoon>

???? </devices>

</domain>

??? 3、libvirt API使用示例

????? (1)[root@localhost qemu]#virsh create /etc/libvirt/qemu/demo.xml

??????? ?[root@localhost qemu]#virsh -c qemu:///session

???? (2)使用API查詢某個域的信息，C語言示例如下：

??? ??#include<stdio.h>

#include<stdlib.h>

#include<libvirt/libvirt.h>

virConnectPtr conn=NULL;

virConnectPtr getConn()

{

??????? ? conn=virConnectOpenReadOnly(NULL);

??????? ? if(conn==NULL)

??????? ? {

?????????? ? printf("error,cann't connect!");

?????????? ? exit(1);

??????? ?? }

??????? ?? return conn;

}

int getInfo(int id)

{

??????? ? virDomainPtr dom=NULL;

??????? ? virDomainInfo info;

??????? ??conn=getConn();

??????? ? dom=virDomainLookupByID(conn,id);

??????? ? if(dom==NULL)

??????? ? {

?????????? ? printf("error,cann't find domain!'");

?????????? ? virConnectClose(conn);

?????????? ? exit(1);

??????? ?? }

??????? ? if (virDomainGetInfo(dom,&info)<0)

??????? ? {

??????? ?? ???printf("error,cann't get info!");

?????????? ?? virDomainFree(dom);

?????????? ?? exit(1);

??????? ?? }

??????? ? ?printf("the Domain state is:%c\n",info.state);

??????? ?? printf("the Domain allowed max memory is:%ld KB\n",info.maxMem);

??????? ?? printf("the Domain used memory is:%ld KB\n",info.memory);

??????? ?? printf("the Domain vCPU number is:%d\n",info.nrVirtCpu);

??????? ?? if(dom!=NULL)

??????? ?? {

?????????? ? virDomainFree(dom);

??????? ?? }

??????? ?? if(conn!=NULL)

??????? ? {

?????????? ? virConnectClose(conn);

??????? ?? }

??????? ? return 0;

}

int main()

{

??????? ? getInfo(1);

??????? ? return 0;

}

??? (3)編譯運行libvirt-conn.c并使用virsh查看當前節點情況

???? ?[root@localhost ~]#virsh

virsh#define /etc/libvirt/qemu/demo.xml

virsh#start libvirt

virsh#list

??? [root@localhost qemu]#ln -s /usr/local/var/run/libvirt /var/run/libvirt

??? virsh#domname1

virsh#dominfo 1

?????? virsh#list

?????? [root@localhost ~]#vncviewer 172.0.0.1:0

問題解決：

一、問題：

?? 1、問題一：configure: error: You must install the libyajl library & headers to compile libvirt

???? ??解決方案：yum install yajl-devel

2、問題：You must install the pciaccess module to build with udev

?? ?解決方案：yum install libpciaccess-devel

3、問題：configure: error: You must install device-mapper-devel/libdevmapper >= 1.0.0 to ?compile libvirt

?? 解決方案：yum install device-mapper-devel

4、出現問題：checking libxml2 xml2-config >= 2.6.0 ... configure: error: Could not find libxml2 anywhere (see config.log for details).

解決方案：yum install libxml2-devel

5、問題：configure: error: libnl-devel >= 1.1 is required for macvtap support
解決方案： yum -y install libnl-devel

6、問題：啟動Libvirt出現問題：libvirtd: error: Unable to obtain pidfile. Check /var/log/messages or run without --daemon for more

解決方案：

（1）查找到libvirtd.pid文件，根據libvirt的安裝不同，位置可能不同：

$ sudo find / -name libvirtd.pid

[sudo] password for cloud:

/usr/local/var/run/libvirtd.pid

（2）刪除：$sudo rm /usr/local/var/run/libvirtd.pid

（3）啟動：$sudo libvirtd -d