KVM学习收集1

全栈工程师修炼指南

发布于 2022-09-29 19:31:30

4680

发布于 2022-09-29 19:31:30

文章被收录于专栏：全栈工程师修炼之路

[TOC]

0x00 基础环境

环境准备:

1) VMware Workstation 16

2) OS 版本&架构: CentOS/7.9.2009/x86_64/ 官网下载地址

# 需求选择:此处测试选择使用 `CentOS-7-x86_64-DVD-2009.iso` 进行安装桌面版本的操作,选择CentOS-7-x86_64-Minimal-2009.iso进行KVM虚拟机安装
CentOS-7-x86_64-DVD-2009.iso                       04-Nov-2020 19:37      4G
CentOS-7-x86_64-DVD-2009.iso                       04-Nov-2020 19:37      4G
CentOS-7-x86_64-DVD-2009.torrent                   06-Nov-2020 22:44    176K
CentOS-7-x86_64-Everything-2009.iso                02-Nov-2020 23:18     10G
CentOS-7-x86_64-Everything-2009.torrent            06-Nov-2020 22:44    381K
CentOS-7-x86_64-Minimal-2009.iso                   03-Nov-2020 22:55    973M
CentOS-7-x86_64-Minimal-2009.torrent               06-Nov-2020 22:44     39K
CentOS-7-x86_64-NetInstall-2009.iso                27-Oct-2020 00:26    575M
CentOS-7-x86_64-NetInstall-2009.torrent            06-Nov-2020 22:44     23K

0x01 基础步骤

描述: 当基础环境准备好后我们就需要开始创建 KVM-Server 的虚拟机了，在我们准备的 VMware Workstation 16 进行配置基础的操作系统，然后在此系统中安装KVM相应软件。

Step 1.如图所示根据需求进行配置虚拟机，注意必须勾选虚拟化引擎来或者硬件辅助虚拟化的支持，例如虚拟化 Intel VT-x/EPT 或 AMD-V/RVI(V)

WeiyiGeek.VM虚拟机创建

Step 2.选择创建带有桌面的CentOS 7的版本，并且开启网络和设置主机名称方便后续连接。

WeiyiGeek.KVM-Server虚拟配置

Step 3.安装完成启动系统并进入以下界面后，输入对于的命令进行简单设置与查看

# (0) 内核查看 (一般正常版本在2.6以上)
$ uname -a
Linux kvm-server 3.10.0-1160.el7.x86_64 #1 SMP Mon Oct 19 16:18:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux


# (1) 关闭和禁用防火墙
[root@kvm-server ~]# systemctl stop firewalld.service 
[root@kvm-server ~]# systemctl disable firewalld.service 
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.

# (2) 关闭selinux
[root@kvm-server ~]# sed -i "s/^SELINUX=enforcing/SELINUX=disabled/g" /etc/sysconfig/selinux 
[root@kvm-server ~]# setenforce 0

# (3) 查看CPU是否支持VT技术
grep -E 'vmx|svm' /proc/cpuinfo 
# 本机支持的vmx的虚拟化即Intel的处理器支持的。(有几个处理器就显示几个flags)
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

WeiyiGeek.简单设置与查看

Step 4.环境清理卸载系统原本存在的KVM以及安装新的软件

# 1.旧的版本
rpm -qa | egrep 'qemu|virt|kvm'
  # libvirt-daemon-driver-nwfilter-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-storage-mpath-4.5.0-36.el7.x86_64
  # libvirt-libs-4.5.0-36.el7.x86_64
  # libvirt-gobject-1.0.0-1.el7.x86_64
  # qemu-guest-agent-2.12.0-3.el7.x86_64
  # libvirt-daemon-driver-storage-logical-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-interface-4.5.0-36.el7.x86_64
  # libvirt-glib-1.0.0-1.el7.x86_64
  # libgovirt-0.3.4-5.el7.x86_64
  # virt-what-1.18-4.el7.x86_64
  # libvirt-daemon-driver-storage-disk-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-storage-gluster-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-storage-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-network-4.5.0-36.el7.x86_64
  # libvirt-daemon-config-network-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-nodedev-4.5.0-36.el7.x86_64
  # qemu-img-1.5.3-175.el7.x86_64
  # libvirt-daemon-driver-storage-core-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-storage-iscsi-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-storage-rbd-4.5.0-36.el7.x86_64
  # qemu-kvm-common-1.5.3-175.el7.x86_64
  # libvirt-daemon-driver-qemu-4.5.0-36.el7.x86_64
  # libvirt-daemon-driver-secret-4.5.0-36.el7.x86_64
  # ipxe-roms-qemu-20180825-3.git133f4c.el7.noarch
  # qemu-kvm-1.5.3-175.el7.x86_64
  # libvirt-daemon-driver-storage-scsi-4.5.0-36.el7.x86_64
  # libvirt-daemon-kvm-4.5.0-36.el7.x86_64
  # libvirt-gconfig-1.0.0-1.el7.x86_64
  # libvirt-daemon-4.5.0-36.el7.x86_64

# 2.卸载
yum remove `rpm -qa | egrep 'qemu|virt|kvm'` -y

# 3.清空目录文件夹
rm -rf /var/lib/libvirt/ /etc/libvirt

# 4.安装软件（如果安装过程出错请检查是否是操作系统的问题-此处我是很顺利的）
yum install *qemu* *virt* librbd1-devel -y  # CentOS 7
# yum upgrade rpm -y && yum install *qemu* *virt* librbd1-devel -y  # CentOS 8

Step 5.在所谓的KVM技术中运用到的就是 QEMU+KVM的组合实现真正意义上的服务器虚拟化。

- KVM : 负责 CPU的虚拟化 + 内存的虚拟化 但却不能模拟其它设备。
- QEMU : 负责 IO设备的模拟例如磁盘 和 网络
# 安装的包简单介绍
1) qemu-kvm : 主包
2) libvirt : 调用KVM虚拟机技术的 Api 接口主要用于管理的作用。
3) virt-manager : 图形管理程序与hypervisor进行交互的作用。

Step 6.安装完成后启动libvirtd服务并查看KVM模块是是否安装

[root@kvm-server ~]# systemctl start libvirtd.service && systemctl enable libvirtd.service
[root@kvm-server ~]# lsmod | grep "kvm"
kvm_intel             188740  0 
kvm                   637289  1 kvm_intel
irqbypass              13503  1 kvm

0x02 安装 GuestOS

GuestOS安装的几种方式:

1.图形化方式
2.完全文本模式 (现场配置虚拟机的规格)
3.命令行模式 (模板镜像 + 配置文件)

1.图形化方式

Step 1.可以通过命令行模式或者在界面中点击运行虚拟系统管理器都可以

virt-manager

WeiyiGeek.virt-manager

Step 2.选择本地介质安装(采用前面我们下载的CentOS精简版镜像),其安装虚拟机方式与VMware类似，不在类似请看下图

WeiyiGeek.VM虚拟机新建

Step 3.QEMU/KVM 创建的VM1虚拟机配置查看，并且点击开始安装，后续centos7安装流程大致相同此处不在讲述。

WeiyiGeek.QEMU/KVM

Step 4.GuestOS 安装成功重启机器。

WeiyiGeek.GuestOS

Tips : 宿主机必须开启路由转发(才能使用桥接网络·重点)之后重启一下 libvirtd.service

echo 'net.ipv4.ip_forward = 1' | tee -a /etc/sysctl.conf && sysctl -p
systemctl restart libvirtd.service

2.完全文本模式

描述: 此种方式应用环境是服务器与客户端均没有图形界面时的场景使用。

Step 1.安装前查看你KVM支持的OS版本;

root@kvm-server ~]# osinfo-query os | grep centos
centos-stream8       | CentOS Stream 8                                    | 8        | http://centos.org/centos-stream/8       
centos5.0            | CentOS 5.0                                         | 5.0      | http://centos.org/centos/5.0            
centos5.1            | CentOS 5.1                                         | 5.1      | http://centos.org/centos/5.1            
centos5.10           | CentOS 5.10                                        | 5.10     | http://centos.org/centos/5.10           
centos5.11           | CentOS 5.11                                        | 5.11     | http://centos.org/centos/5.11           
centos5.2            | CentOS 5.2                                         | 5.2      | http://centos.org/centos/5.2            
centos5.3            | CentOS 5.3                                         | 5.3      | http://centos.org/centos/5.3            
centos5.4            | CentOS 5.4                                         | 5.4      | http://centos.org/centos/5.4            
centos5.5            | CentOS 5.5                                         | 5.5      | http://centos.org/centos/5.5            
centos5.6            | CentOS 5.6                                         | 5.6      | http://centos.org/centos/5.6            
centos5.7            | CentOS 5.7                                         | 5.7      | http://centos.org/centos/5.7            
centos5.8            | CentOS 5.8                                         | 5.8      | http://centos.org/centos/5.8            
centos5.9            | CentOS 5.9                                         | 5.9      | http://centos.org/centos/5.9            
centos6.0            | CentOS 6.0                                         | 6.0      | http://centos.org/centos/6.0            
centos6.1            | CentOS 6.1                                         | 6.1      | http://centos.org/centos/6.1            
centos6.10           | CentOS 6.10                                        | 6.10     | http://centos.org/centos/6.10           
centos6.2            | CentOS 6.2                                         | 6.2      | http://centos.org/centos/6.2            
centos6.3            | CentOS 6.3                                         | 6.3      | http://centos.org/centos/6.3            
centos6.4            | CentOS 6.4                                         | 6.4      | http://centos.org/centos/6.4            
centos6.5            | CentOS 6.5                                         | 6.5      | http://centos.org/centos/6.5            
centos6.6            | CentOS 6.6                                         | 6.6      | http://centos.org/centos/6.6            
centos6.7            | CentOS 6.7                                         | 6.7      | http://centos.org/centos/6.7            
centos6.8            | CentOS 6.8                                         | 6.8      | http://centos.org/centos/6.8            
centos6.9            | CentOS 6.9                                         | 6.9      | http://centos.org/centos/6.9            
centos7.0            | CentOS 7                                           | 7        | http://centos.org/centos/7.0            
centos8              | CentOS 8                                           | 8        | http://centos.org/centos/8

Step 2.安装命令;

# 1.帮助查看
man virt-install 

# 2.采用FTP的格式进行安装(注意需要将OS镜像挂载到此ftp目录下)
virt-install --connnect qemu:///system \
-n vm3 -r 2048 --vcpus=1 --disk-path=/var/lib/libvirt/images/vm9.img,size=7 \
--os-type=linux --os-variant=centos7.0 -x console=ttyS0 --nographics \
--location=ftp://192.168.10.230/centos7/

TIPS : 安装时给与的内存必须是2G及以上否则将报如下错误 Dracut-Initqueue[552]:/sbin/dmsquash-live-root:line 273: printf: write error : no space left on device。

3.命令行模式 (推荐方式)

描述: 通过此魔术我们可以轻松的创建我们的虚拟机，此种模式创建虚拟机依赖于虚拟机配置文件和虚拟机虚拟机img介质。

Step 1.虚拟机组成部分

[root@kvm-server ~]# ls /etc/libvirt/qemu
networks  vm1.xml
[root@kvm-server ~]# ls /var/lib/libvirt/images/
vm1.qcow2

Step 2.根据现有模板镜像配置文件创建虚拟机即复制磁盘镜像与配置文件

[root@kvm-server ~]# cp /etc/libvirt/qemu/vm1.xml /etc/libvirt/qemu/vm2.xml
[root@kvm-server ~]# cp /var/lib/libvirt/images/vm1.qcow2 /var/lib/libvirt/images/vm2.qcow2

Step 3.配置文件修改

# 1.虚拟机UUID修改
[root@kvm-server ~]# uuidgen 
960cc2bb-9731-4101-94e6-160c4263bace

# 2.虚拟机配置文件
<!--
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 vm2 or other application using the libvirt API.
-->

<domain type='kvm'>
  <!-- 修改点1.名称与UUID -->
  <name>vm2</name>
  <uuid>960cc2bb-9731-4101-94e6-160c4263bace</uuid>
  <memory unit='KiB'>2097152</memory>
  <currentMemory unit='KiB'>2097152</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'>Broadwell-noTSX-IBRS</model>
    <feature policy='require' name='md-clear'/>
    <feature policy='require' name='spec-ctrl'/>
    <feature policy='require' name='ssbd'/>
  </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>
    <!-- 修改点2.虚拟机磁盘镜像  -->
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/vm2.qcow2'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <target dev='hda' bus='ide'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x7'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci1'>
      <master startport='0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0' multifunction='on'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci2'>
      <master startport='2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x1'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci3'>
      <master startport='4'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </controller>
    <!-- 修改点3.网络Mac地址(virtio == NAT 转发) -->
    <interface type='network'>
      <mac address='52:54:00:64:97:40'/>
      <source network='default'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      </target>
    </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>
    <channel type='spicevmc'>
      <target type='virtio' name='com.redhat.spice.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='2'/>
    </channel>
    <input type='tablet' bus='usb'>
      <address type='usb' bus='0' port='1'/>
    </input>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <graphics type='spice' autoport='yes'>
      <listen type='address'/>
      <image compression='off'/>
    </graphics>
    <sound model='ich6'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </sound>
    <video>
      <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <redirdev bus='usb' type='spicevmc'>
      <address type='usb' bus='0' port='2'/>
    </redirdev>
    <redirdev bus='usb' type='spicevmc'>
      <address type='usb' bus='0' port='3'/>
    </redirdev>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </memballoon>
    <rng model='virtio'>
      <backend model='random'>/dev/urandom</backend>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
    </rng>
  </devices>
</domain>

Step 4.虚拟机创建

[root@kvm-server ~]# virsh define /etc/libvirt/qemu/vm2.xml
# 定义域 vm2（从 /etc/libvirt/qemu/vm2.xml）

Step 5.宿主机开启路由转发(才能使用桥接网络重点)之后重启一哈 libvirtd.service

echo 'net.ipv4.ip_forward = 1' | tee -a /etc/sysctl.conf && sysctl -p
systemctl restart libvirtd.service

Step 6.虚拟机运行结果

WeiyiGeek.成功创建并连接

4.飞机舱cockpit管理KVM服务器

Tips : 我们可以使用飞机驾驶舱安装与管理虚拟机实际上就是通过一个Web界面来管理服务器，安装完成后浏览器访问服务地址: 9090

# 安装&启用
yum install cockpit -y; \
systemctl start cockpit

# 服务地址查看
ip addr | grep "    inet "
  # inet 127.0.0.1/8 scope host lo
  # inet 192.168.228.128/24 brd 192.168.228.255 scope global noprefixroute dynamic ens33

# 停止服务
systemctl stop cockpit.socket

# 端口配置
vim /etc/systemd/system/cockpit.socket.d/listen.conf
# [Unit]
# Description=Cockpit Web Service Socket
# Documentation=man:cockpit-ws(8)
# Wants=cockpit-motd.service

# [Socket]
# ListenStream=9090
# ExecStartPost=-/usr/share/cockpit/motd/update-motd '' localhost
# ExecStartPost=-/bin/ln -snf active.motd /run/cockpit/motd
# ExecStopPost=-/bin/ln -snf /usr/share/cockpit/motd/inactive.motd /run/cockpit/motd

# [Install]
# WantedBy=sockets.target

sudo systemctl daemon-reload
sudo systemctl restart cockpit.socket
sudo systemctl restart cockpit.service

WeiyiGeek.cockpit-Web

0x03 升级GuestOS

描述: 在实际的应用场景中,我们常常要对已安装的GuestOS进行添加硬件设备和升级现有的资源配置。

实现方式说明

1.图像界面操作(简单)
2.配置文件操作(手动-无界面的情况下)

图像界面操作

虚拟机添加网卡设备流程

Step 1.首先需要关闭要添加硬件的虚拟机
Step 2.双击虚拟机在打开的对话框点击上方的 View 并点击 Details(详情)，点击 Add Hardware就可以选择要添加的虚拟硬件;
Step 3.此处以添加网卡为例。

Step 4.删除添加的虚拟硬件步骤点击要删除的硬件, 例如NIC:20:b9:da然后点击右下角的删除即可。

配置文件操作

虚拟机添加磁盘设备流程

Step 1.同样需要先关闭要添加硬件的虚拟机VM2;

Step 2.创建要添加的磁盘镜像文件(qcow2格式);

$ qemu-img create -f qcow2 /var/lib/libvirt/images/vm2-1.qcow2 1G
> Formatting '/var/lib/libvirt/images/vm2-1.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off

Step 3.编辑VM2虚拟主机的配置文件,找到定义磁盘镜像的<disk>标签, 将该标签及其包含的内容复制一份在其后。

$ virsh edit vm2
37     <disk type='file' device='disk'>
38       <driver name='qemu' type='qcow2'/>
39       <source file='/var/lib/libvirt/images/vm2.qcow2'/>
40       <target dev='vda' bus='virtio'/>
41       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
42     </disk>
43     <disk type='file' device='disk'>
44       <driver name='qemu' type='qcow2'/>
45       <source file='/var/lib/libvirt/images/vm2-1.qcow2'/> <!--修改点: 磁盘镜像名称-->
46       <target dev='vdb' bus='virtio'/>  <!--修改点: 物理磁盘名称-->
47       <address type='pci' domain='0x0000' bus='0x00' slot='0x17' function='0x0'/> <!--修改点: 一定插槽值不能重复-->
48     </disk>
# 编辑了域 vm2 XML 配置。

Step 4.修改完VM2虚拟机配置后保存:wq之后重启libvirtd服务, 之后采用命令启动虚拟机

[root@kvm-server ~]# systemctl restart libvirtd.service 
[root@kvm-server ~]# virsh list --all
 Id    名称                         状态
----------------------------------------------------
 -     vm1                            关闭
 -     vm2                            关闭
[root@kvm-server ~]# virsh start vm2
域 vm2 已开始