KVM部署
文章目录
虚拟化介绍
虚拟化是云计算的基础。简单的说，虚拟化使得在一台物理的服务器上可以跑多台虚拟机，虚拟机共享物理机的 CPU、内存、IO 硬件资源，但逻辑上虚拟机之间是相互隔离的。
物理机我们一般称为宿主机（Host），宿主机上面的虚拟机称为客户机（Guest）。
那么 Host 是如何将自己的硬件资源虚拟化，并提供给 Guest 使用的呢？
这个主要是通过一个叫做 Hypervisor 的程序实现的。
根据 Hypervisor 的实现方式和所处的位置，虚拟化又分为两种：
- 全虚拟化
- 半虚拟化
全虚拟化：
Hypervisor 直接安装在物理机上，多个虚拟机在 Hypervisor 上运行。Hypervisor 实现方式一般是一个特殊定制的 Linux 系统。Xen 和 VMWare 的 ESXi 都属于这个类型
半虚拟化：
物理机上首先安装常规的操作系统，比如 Redhat、Ubuntu 和 Windows。Hypervisor 作为 OS 上的一个程序模块运行，并对管理虚拟机进行管理。KVM、VirtualBox 和 VMWare Workstation 都属于这个类型
理论上讲：
全虚拟化一般对硬件虚拟化功能进行了特别优化，性能上比半虚拟化要高；
半虚拟化因为基于普通的操作系统，会比较灵活，比如支持虚拟机嵌套。嵌套意味着可以在KVM虚拟机中再运行KVM。
kvm介绍
kVM 全称是 Kernel-Based Virtual Machine。也就是说 KVM 是基于 Linux 内核实现的。
KVM有一个内核模块叫 kvm.ko，只用于管理虚拟 CPU 和内存。
那 IO 的虚拟化，比如存储和网络设备则是由 Linux 内核与Qemu来实现。
作为一个 Hypervisor，KVM 本身只关注虚拟机调度和内存管理这两个方面。IO 外设的任务交给 Linux 内核和 Qemu。
大家在网上看 KVM 相关文章的时候肯定经常会看到 Libvirt 这个东西。
Libvirt 就是 KVM 的管理工具。
其实，Libvirt 除了能管理 KVM 这种 Hypervisor，还能管理 Xen，VirtualBox 等。
Libvirt 包含 3 个东西：后台 daemon 程序 libvirtd、API 库和命令行工具 virsh
- libvirtd是服务程序，接收和处理 API 请求；
- API 库使得其他人可以开发基于 Libvirt 的高级工具，比如 virt-manager，这是个图形化的 KVM 管理工具；
- virsh 是我们经常要用的 KVM 命令行工具
kvm部署
环境说明：
| 系统类型 | IP |
|---|---|
| Centos8 | 192.168.240.60 |
kvm安装
部署前请确保你的CPU虚拟化功能已开启。分为两种情况：
- 虚拟机要关机设置CPU虚拟化
- 物理机要在BIOS里开启CPU虚拟化
关闭防火墙跟selinux
[root@KVM ~]# systemctl disable --now firewalld.service
Removed /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@KVM ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@KVM ~]# setenforce 0
下载源
[root@KVM ~]# yum -y install epel-release vim wget net-tools unzip zip gcc gcc-c++
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
[root@KVM ~]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
vmx
vmx
vmx
kvm安装
[root@KVM ~]# yum -y install qemu-kvm qemu-kvm-common qemu-img virt-manager libvirt python3-libvirt libvirt-client virt-install virt-viewer bridge-utils libguestfs-tools
因为虚拟机中网络，我们一般都是和公司的其他服务器是同一个网段，所以我们需要把
KVM服务器的网卡配置成桥接模式。这样的话KVM的虚拟机就可以通过该桥接网卡和公司内部
其他服务器处于同一网段
此处我的网卡是ens33，所以用br0来桥接ens33网卡
[root@KVM ~]# cat /etc/sysconfig/network-scripts/ifcfg-br0
TYPE=Bridge
DEVICE=br0
BOOTPROTO=static
NAME=br0
ONBOOT=yes
IPADDR=192.168.240.60
NATEMASK=255.255.255.0
GATEWAY=192.168.240.2
DNS1=114.114.114.114
[root@KVM ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
NAME=ens33
DEVICE=ens33
ONBOOT=yes
BRIDGE=br0
[root@KVM ~]# systemctl restart NetworkManager
[root@KVM ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UP group default qlen 1000
link/ether 00:0c:29:11:4d:9c brd ff:ff:ff:ff:ff:ff
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 52:54:00:98:c4:82 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
link/ether 52:54:00:98:c4:82 brd ff:ff:ff:ff:ff:ff
5: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:0c:29:11:4d:9c brd ff:ff:ff:ff:ff:ff
inet 192.168.240.60/24 brd 192.168.240.255 scope global noprefixroute br0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe11:4d9c/64 scope link
valid_lft forever preferred_lft forever
启动服务
[root@KVM ~]# systemctl start libvirtd
[root@KVM ~]# systemctl enable libvirtd
验证安装结果
[root@KVM ~]# lsmod | grep kvm
kvm_intel 311296 0
kvm 839680 1 kvm_intel
irqbypass 16384 1 kvm
测试并验证安装结果
[root@KVM ~]# virsh -c qemu:///system list
Id 名称 状态
-------------------
[root@KVM ~]# virt-install --version
2.2.1
[root@KVM ~]# ln -s /usr/libexec/qemu-kvm /usr/local/qemu-kvm
[root@KVM ~]# lsmod |grep kvm
kvm_intel 311296 0
kvm 839680 1 kvm_intel
irqbypass 16384 1 kvm
[root@KVM ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29114d9c no ens33
virbr0 8000.52540098c482 yes virbr0-nic
kvm web管理界面安装
kvm 的 web 管理界面是由 webvirtmgr 程序提供的。
安装依赖包
[root@localhost ~]# yum -y install epel-release
[root@localhost ~]# yum -y install git python-pip libvirt-python libxml2-python python-websockify supervisor nginx python-devel
从github上下载webvirtmgr代码
[root@localhost ~]# cd /usr/local/src/
[root@localhost ~]# git clone git://github.com/retspen/webvirtmgr.git
正克隆到 'webvirtmgr'...
remote: Enumerating objects: 5614, done.
remote: Total 5614 (delta 0), reused 0 (delta 0), pack-reused 5614
接收对象中: 100% (5614/5614), 2.97 MiB | 687.00 KiB/s, done.
处理 delta 中: 100% (3606/3606), done.
[root@kvm-web src]# cd webvirtmgr/
[root@localhost ~]# pip install --upgrade pip
Collecting pip
Downloading https://files.pythonhosted.org/packages/00/5f/d6959d6f25f202e3e68e3a53b815af42d770c829c19382d0acbf2c3e2112/pip-21.3.tar.gz (1.7MB)
100% |████████████████████████████████| 122kB 241kB/s
Collecting lockfile>=0.9 (from -r requirements.txt (line 5))
Downloading https://files.pythonhosted.org/packages/c8/22/9460e311f340cb62d26a38c419b1381b8593b0bb6b5d1f056938b086d362/lockfile-0.12.2-py2.py3-none-any.whl
Installing collected packages: django, gunicorn, lockfile
Running setup.py install for django ... done
Successfully installed django-1.5.5 gunicorn-19.5.0 lockfile-0.12.2
You are using pip version 8.1.2, however version 21.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
检查sqlite3是否安装
[root@localhost webvirtmgr]# python
Python 2.7.5 (default, Nov 16 2020, 22:23:17)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sqlite3
>>> exit ()
初始化帐号信息
[root@localhost webvirtmgr]# python manage.py syncdb
WARNING:root:No local_settings file found.
Creating tables ...
Creating table auth_permission
······
Creating table create_flavor
You just installed Django's auth system, which means you don't have any superusers defined.
Would you like to create one now? (yes/no): yes ##问你是否创建超级管理员帐号
Username (leave blank to use 'root'): admin ##指定超级管理员帐号用户名，默认留空为root
Email address: 123@qq.com ##设置超级管理员邮箱
Password: ##设置超级管理员密码
Password (again): ##再次输入超级管理员密码
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
Installed 6 object(s) from 1 fixture(s)
拷贝web网页至指定目录
[root@localhost webvirtmgr]# mkdir /var/www
[root@localhost webvirtmgr]# cp -r /usr/local/src/webvirtmgr /var/www/
[root@localhost webvirtmgr]# chown -R nginx.nginx /var/www/webvirtmgr/
生成密钥
[root@localhost ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:ZG+SvgplJDTnKHPBm+b/P2JXM8T0MvkEdfbUm0DMfy8 root@KVM
The key's randomart image is:
+---[RSA 3072]----+
| .+ . +o. =|
| ..* o+ +o|
| o +oo o o +o +|
| ++o o o * o+.|
| o o S o. = o|
| .o . o + E .|
| .. . . o . |
| .. o.o |
| .+o+.. |
+----[SHA256]-----+
##kvm部署在其他机器，那么这个是它的ip
[root@localhost ~]# ssh-copy-id 192.168.240.60
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.240.60 (192.168.240.60)' can't be established.
ECDSA key fingerprint is SHA256:YDPxPR7Nqao+hwjww9kCBH/G0mbpOsvhSahI6YKiRhQ.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.240.60's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.240.60'"
and check to make sure that only the key(s) you wanted were added.
配置端口转发
[root@localhost ~]# ssh 192.168.240.60 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
Last login: Wed Oct 20 02:49:10 2021 from 192.168.240.1
[root@localhost ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:111 0.0.0.0:*
LISTEN 0 32 192.168.122.1:53 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 127.0.0.1:6080 0.0.0.0:*
LISTEN 0 128 127.0.0.1:8000 0.0.0.0:*
LISTEN 0 128 [::]:111 [::]:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 128 [::1]:6080 [::]:*
LISTEN 0 128 [::1]:8000 [::]:*
配置nginx
[root@localhost ~]# vim /etc/nginx/nginx.conf
38 server {
39 listen 80 default_server; ##改成listen 80;
40 listen [::]:80 default_server; ##删除该行
41 server_name _; ##改为server_name localhost;
42 root /usr/share/nginx/html;##删除该行
45 location / {
46 root html; ##添加该行
47 index index.html index.htm; ##添加该行
48 }
[root@localhost ~]# vi /etc/nginx/conf.d/webvirtmgr.conf
[root@localhost ~]# cat /etc/nginx/conf.d/webvirtmgr.conf
server {
listen 80 default_server;
server_name $hostname;
#access_log /var/log/nginx/webvirtmgr_access_log;
location /static/ {
root /var/www/webvirtmgr/webvirtmgr;
expires max;
}
location / {
proxy_pass http://127.0.0.1:8000;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-for $proxy_add_x_forwarded_for;
proxy_set_header Host $host:$server_port;
proxy_set_header X-Forwarded-Proto $remote_addr;
proxy_connect_timeout 600;
proxy_read_timeout 600;
proxy_send_timeout 600;
client_max_body_size 1024M;
}
}
##确保bind绑定的是本机的8000端口
[root@localhost ~]# vim /var/www/webvirtmgr/conf/gunicorn.conf.py
······
bind = '0.0.0.0:8000'
backlog = 2048
·····
重启nginx
[root@localhost ~]# systemctl restart nginx
[root@localhost ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:111 0.0.0.0:*
LISTEN 0 128 0.0.0.0:80 0.0.0.0:*
LISTEN 0 32 192.168.122.1:53 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 127.0.0.1:6080 0.0.0.0:*
LISTEN 0 128 127.0.0.1:8000 0.0.0.0:*
LISTEN 0 128 [::]:111 [::]:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 128 [::1]:6080 [::]:*
LISTEN 0 128 [::1]:8000 [::]:*
设置supervisor
[root@localhost ~]# vim /etc/supervisord.conf
.....此处省略上面的内容，在文件最后加上以下内容
[program:webvirtmgr]
command=/usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /var/www/webvirtmgr/conf/gunicorn.conf.py
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
logfile=/var/log/supervisor/webvirtmgr.log
log_stderr=true
user=nginx
[program:webvirtmgr-console]
command=/usr/bin/python2 /var/www/webvirtmgr/console/webvirtmgr-console
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
stdout_logfile=/var/log/supervisor/webvirtmgr-console.log
redirect_stderr=true
user=nginx
启动supervisor并设置开机自启
[root@localhost ~]# systemctl start supervisord
[root@localhost ~]# systemctl enable supervisord
Created symlink /etc/systemd/system/multi-user.target.wants/supervisord.service → /usr/lib/systemd/system/supervisord.service.
[root@KVM ~]# systemctl status supervisord
● supervisord.service - Process Monitoring and Control Daemon
Loaded: loaded (/usr/lib/systemd/system/supervisord.servi>
Active: active (running) since Wed 2021-10-20 03:39:38 ED>
Main PID: 95670 (supervisord)
Tasks: 2 (limit: 37334)
Memory: 39.9M
CGroup: /system.slice/supervisord.service
├─95670 /usr/bin/python3.6 /usr/bin/supervisord ->
└─96139 /usr/bin/python2 /var/www/webvirtmgr/mana>
10月 20 03:39:37 KVM systemd[1]: Starting Process Monitoring>
10月 20 03:39:38 KVM systemd[1]: Started Process Monitoring >
lines 1-12/12 (END)
配置nginx用户
[root@localhost ~]# su - nginx -s /bin/bash
-bash-4.2$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/var/lib/nginx/.ssh/id_rsa):
Created directory '/var/lib/nginx/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /var/lib/nginx/.ssh/id_rsa.
Your public key has been saved in /var/lib/nginx/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:4Q33RY2cSwrTYrEKxrKB9Uk2hXXgZcrqK8L4VEgrMHA nginx@kvm-web
The key's randomart image is:
+---[RSA 2048]----+
|. E . +++.=o ..+ |
|.. o =.= ==...= .|
|o o o * *.o+ o.. |
|.o o = + * .... |
|. o o . S . . |
| . . . |
| o. . |
|..o . . |
| ... .. |
+----[SHA256]-----+
-bash-4.2$ touch ~/.ssh/config && echo -e "StrictHostKeyChecking=no\nUserKnownHostsFile=/dev/null" >> ~/.ssh/config
-bash-4.2$ chmod 0600 ~/.ssh/config
-bash-4.2$ ssh-copy-id root@192.168.240.60
/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/var/lib/nginx/.ssh/id_rsa.pub"
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
Warning: Permanently added '192.168.240.60' (ECDSA) to the list of known hosts.
root@192.168.240.60's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh 'root@192.168.240.60'"
and check to make sure that only the key(s) you wanted were added.
[nginx@localhost ~]$ exit
[root@localhost ~]# vim /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@KVM ~]# cat /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[Remote libvirt SSH access]
Identity=unix-user:root
Action=org.libvirt.unix.manage
ResultAny=yes
ResultInactive=yes
ResultActive=yes
[root@localhost ~]# chown -R root.root /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@localhost ~]# systemctl restart nginx
[root@localhost ~]# systemctl restart libvirtd
[root@localhost ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:111 0.0.0.0:*
LISTEN 0 128 0.0.0.0:80 0.0.0.0:*
LISTEN 0 32 192.168.122.1:53 0.0.0.0:*
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 127.0.0.1:6080 0.0.0.0:*
LISTEN 0 128 127.0.0.1:8000 0.0.0.0:*
LISTEN 0 128 [::]:111 [::]:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 128 [::1]:6080 [::]:*
LISTEN 0 128 [::1]:8000 [::]:*
通过远程连接软件上传ISO镜像文件至存储目录/var/lib/libvirt/images/
[root@KVM images]# ls
[root@KVM images]#
[root@KVM images]# ls
CentOS-Stream-8-x86_64-20201211-dvd1.iso
在 web 界面查看ISO镜像是否存在
创建系统安装镜像
添加成功如下图所示
kvm网络管理
添加桥接网络
实例管理
实例(虚拟机)创建
虚拟机插入光盘
设置在 web *问虚拟机的密码
启动虚拟机
虚拟机安装
故障案例
案例1
web界面配置完成后可能会出现以下错误界面
解决方法是安装novnc并通过novnc_server启动一个vnc
[root@localhost ~]# ll /etc/rc.local
lrwxrwxrwx. 1 root root 13 Aug 6 2018 /etc/rc.local -> rc.d/rc.local
[root@localhost ~]# ll /etc/rc.d/rc.local
-rw-r--r-- 1 root root 513 Mar 11 22:35 /etc/rc.d/rc.local
[root@localhost ~]# chmod +x /etc/rc.d/rc.local
[root@localhost ~]# ll /etc/rc.d/rc.local
-rwxr-xr-x 1 root root 513 Mar 11 22:35 /etc/rc.d/rc.local
[root@localhost ~]# vim /etc/rc.d/rc.local
......此处省略N行
# that this script will be executed during boot.
touch /var/lock/subsys/local
nohup novnc_server 172.16.12.128:5920 &
[root@localhost ~]# . /etc/rc.d/rc.local
做完以上操作后再次访问即可正常访问
案例2
第一次通过web访问kvm时可能会一直访问不了，一直转圈，而命令行界面一直报错(too many open files)
此时需要对nginx进行配置
[root@localhost ~]# vim /etc/nginx/nginx.conf
....此处省略N行
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
worker_rlimit_nofile 655350; //添加此行配置
# Load dynamic modules. See /usr/share/nginx/README.dynamic.
....此处省略N行
[root@localhost ~]# systemctl restart nginx
然后对系统参数进行设置
[root@localhost ~]# vim /etc/security/limits.conf
....此处省略N行
# End of file
* soft nofile 655350
* hard nofile 655350
到此问题即可解决