KVM虚拟化

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所属分类:linux技术
摘要

虚拟化:在一台计算机上虚拟出多个逻辑的计算机,而且每个逻辑计算机
它可以是不同操作系统

虚拟化介绍

虚拟化:在一台计算机上虚拟出多个逻辑的计算机,而且每个逻辑计算机
它可以是不同操作系统

虚拟化技术:可以扩大硬件容量,单个cpu模拟出多个cpu并行,
允许一个平台上同时运行多个操作系统,应用程序都可以在相互独立
的空间内运行,而且互不影响。

为什么企业使用虚拟化技术

1、节约成本
2、提高效率,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。
Hypervisor:一种运行在物理服务器硬件与操作系统之间的中间软件层
可允许多个操作系统和应用来共享硬件资源
根据 Hypervisor 的实现方式和所处的位置,虚拟化又分为两种:
完全虚拟化:直接在物理机上部署虚拟化,且不需要修改操作系统内核
半虚拟化:需要修改操作系统内核,使其支持虚拟化驱动来实现虚拟化技术

全虚拟化
KVM虚拟化

半虚拟化
KVM虚拟化

kvm简介

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。

Qemu-KVM虚拟化

KVM本身不执行任何设备模拟,需要用户空间程序QEMU通过/dev/kvm接口设置一个虚拟客户机的地址空间。

KVM和Qemu的关系

Qemu是一个独立的虚拟化解决方案,通过intel-VT 或AMD SVM实现全虚拟化,安装qemu的系统,可以直接模拟出另一个完全不同的系统环境。QEMU本身可以不依赖于KVM,但是如果有KVM的存在并且硬件(处理器)支持比如Intel VT功能,那么QEMU在对处理器虚拟化这一块可以利用KVM提供的功能来提升性能。
KVM是集成到Linux内核的Hypervisor,是X86架构且硬件支持虚拟化技术(Intel-VT或AMD-V)的Linux的全虚拟化解决方案。它是Linux的一个很小的模块,利用Linux做大量的事,如任务调度、内存管理与硬件设备交互等。准确来说,KVM是Linux kernel的一个模块。

Qemu的三种运行模式:

1.第一种模式是通过kqemu模块实现内核态的加速。
2.第二种模式是在用户态直接运行QEMU,由QEMU对目标机的 所有 指令进行翻译后执行,相当于全虚拟化。
3.第三种模式则是KVM官方提供的kvm-qemu加速模式。
qmeu的两种特点:

1.QEMU可以在没有主机内核驱动程序的情况下运行。
2.它适用于多种操作系统(GNU / Linux,* BSD,Mac OS X,Windows)和体系结构。
3.它执行FPU的精确软件仿真。
QEMU的两种操作模式:完整的系统仿真和用户模式仿真。

QEMU用户模式仿真具有以下功能:

1.通用Linux系统调用转换器,包括大部分ioctls。
2.使用本机CPU clone的仿真为线程使用Linux调度程序。
3.通过将主机信号重新映射到目标信号来实现精确信号处理。
QEMU全系统仿真具有以下特点:

1.QEMU使用完整的软件MMU来实现最大的便携性。
2.QEMU可以选择使用内核加速器,如kvm。加速器本地执行大部分客户代码,同时继续模拟机器的其余部分。
3.可以仿真各种硬件设备,并且在某些情况下,客户机操作系统可以透明地使用主机设备(例如串行和并行端口,USB,驱动器)。主机设备传递可用于与外部物理外围设备(例如网络摄像头,调制解调器或磁带驱动器)交谈。
4.对称多处理(SMP)支持。目前,内核加速器需要使用多个主机CPU进行仿真。

部署kvm

环境说明

主机名 ip 系统
kvm 192.168.111.141 centos 8

内存尽量给大点,cpu虚拟化功能都勾选,虚拟计数器看情况勾选
KVM虚拟化

//新建分区,将硬盘所有大小都给这个分区 [root@localhost ~]# lsblk NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT sda           8:0    0  100G  0 disk  |-sda1        8:1    0    1G  0 part /boot `-sda2        8:2    0   99G  0 part    |-cs-root 253:0    0 63.9G  0 lvm  /   |-cs-swap 253:1    0    4G  0 lvm  [SWAP]   `-cs-home 253:2    0 31.2G  0 lvm  /home sdb           8:16   0  200G  0 disk  sr0          11:0    1 10.3G  0 rom   [root@localhost ~]# parted /dev/sdb GNU Parted 3.2 Using /dev/sdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mklabel                                                           New disk label type? msdos                                                 (parted) unit                                                              Unit?  [compact]? MiB                                                      (parted) p                                                                 Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 204800MiB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags:   Number  Start  End  Size  Type  File system  Flags  (parted) mkpart                                                            Partition type?  primary/extended? primary                                 File system type?  [ext2]? xfs                                             Start? 10MiB                                                               End? 204790MiB                                                             (parted) p                                                                 Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 204800MiB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags:   Number  Start    End        Size       Type     File system  Flags  1      10.0MiB  204790MiB  204780MiB  primary  xfs          lba  (parted) q                                                                 Information: You may need to update /etc/fstab.  [root@localhost ~]# udevadm settle  //格式化,挂载 [root@localhost ~]# mkfs.xfs /dev/sdb1 meta-data=/dev/sdb1              isize=512    agcount=4, agsize=13105920 blks          =                       sectsz=512   attr=2, projid32bit=1          =                       crc=1        finobt=1, sparse=1, rmapbt=0          =                       reflink=1    bigtime=0 inobtcount=0 data     =                       bsize=4096   blocks=52423680, imaxpct=25          =                       sunit=0      swidth=0 blks naming   =version 2              bsize=4096   ascii-ci=0, ftype=1 log      =internal log           bsize=4096   blocks=25597, version=2          =                       sectsz=512   sunit=0 blks, lazy-count=1 realtime =none                   extsz=4096   blocks=0, rtextents=0 [root@localhost ~]# blkid /dev/sdb1 /dev/sdb1: UUID="8fff324a-8c2f-4ee2-a7be-518e454d1897" BLOCK_SIZE="512" TYPE="xfs" PARTUUID="b5e26308-01" [root@localhost ~]# mkdir /kvmdata [root@localhost ~]# vim /etc/fstab  UUID=8fff324a-8c2f-4ee2-a7be-518e454d1897 /kvmdata xfs defaults 0 0  [root@localhost ~]# df -Th Filesystem          Type      Size  Used Avail Use% Mounted on devtmpfs            devtmpfs  3.8G     0  3.8G   0% /dev tmpfs               tmpfs     3.8G     0  3.8G   0% /dev/shm tmpfs               tmpfs     3.8G  9.0M  3.8G   1% /run tmpfs               tmpfs     3.8G     0  3.8G   0% /sys/fs/cgroup /dev/mapper/cs-root xfs        64G  2.1G   62G   4% / /dev/sda1           xfs      1014M  211M  804M  21% /boot /dev/mapper/cs-home xfs        32G  255M   31G   1% /home tmpfs               tmpfs     774M     0  774M   0% /run/user/0 /dev/sdb1           xfs       200G  1.5G  199G   1% /kvmdata   //KVM安装 //关闭防火墙和selinux [root@localhost ~]# systemctl disable --now firewalld [root@localhost ~]# setenforce 0 [root@localhost ~]# sed -ri 's/^(SELINUX=).*/1disabled/g' /etc/selinux/config [root@localhost ~]# reboot  //部署yum源 [root@localhost ~]# cd /etc/yum.repos.d/ [root@localhost yum.repos.d]# rm -rf * [root@localhost yum.repos.d]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo [root@localhost yum.repos.d]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo   //安装所需软件包 [root@localhost ~]# yum -y install epel-release [root@localhost ~]# yum -y install vim wget net-tools unzip zip gcc gcc-c++ qemu-kvm  qemu-img virt-manager libvirt libvirt-client virt-install virt-viewer libguestfs-tools --allowerasing  [root@localhost ~]# wget http://mirror.centos.org/centos/7/os/x86_64/Packages/qemu-kvm-tools-1.5.3-175.el7.x86_64.rpm [root@localhost ~]# wget http://mirror.centos.org/centos/7/os/x86_64/Packages/libvirt-python-4.5.0-1.el7.x86_64.rpm [root@localhost ~]# wget http://mirror.centos.org/centos/7/os/x86_64/Packages/bridge-utils-1.5-9.el7.x86_64.rpm [root@localhost ~]# rpm -ivh --nodeps libvirt-python-4.5.0-1.el7.x86_64.rpm [root@localhost ~]# rpm -ivh --nodeps qemu-kvm-tools-1.5.3-175.el7.x86_64.rpm  //验证cpu是否支持kvm,vmx是intel的  svm是AMD的 [root@localhost ~]# egrep -o 'vmx|svm' /proc/cpuinfo vmx  //安装kvm [root@localhost ~]# yum -y install qemu-kvm    qemu-kvm    qemu-img    virt-manager    libvirt    libvirt-python3    libvirt-client    virt-install    virt-viewer    bridge-utils    libguestfs-tools  //配置网络,因为虚拟机中的网络,我们一般是都和公司服务器处在同一网段的,所以我们需要把kvm的网卡配置成桥接模式 [root@localhost ~]# cd /etc/sysconfig/network-scripts/ [root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-br0 [root@localhost network-scripts]# vim ifcfg-br0  TYPE=Bridge BOOTPROTO=static NAME=br0 DEVICE=br0 ONBOOT=yes IPADDR=192.168.111.141 PREFIX=24 GATEWAY=192.168.111.2 DNS=8.8.8.8 [root@localhost network-scripts]# vim ifcfg-ens33  TYPE=Ethernet BOOTPROTO=static NAME=ens33 DEVICE=ens33 ONBOOT=yes BRIDGE=br0  //重启网卡服务 [root@localhost network-scripts]# nmcli connection reload [root@localhost network-scripts]# nmcli connection up ens33 [root@localhost network-scripts]# nmcli connection up br0 [root@localhost network-scripts]# 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:29:50:34:72 brd ff:ff:ff:ff:ff:ff 3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000     link/ether 00:0c:29:50:34:72 brd ff:ff:ff:ff:ff:ff     inet 192.168.111.141/24 brd 192.168.111.255 scope global noprefixroute br0        valid_lft forever preferred_lft forever  //重启libvirtd服务,并设置下次启动生效 [root@localhost ~]# systemctl enable --now libvirtd  //查看kvm模块是否加载 [root@localhost ~]# lsmod |grep kvm kvm_intel             339968  0 kvm                   905216  1 kvm_intel irqbypass              16384  1 kvm  //将qemu-kvm这个命令做一个软链接到/usr/bin/qemu-kvm [root@localhost ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm [root@localhost ~]# ll /usr/bin/qemu-kvm lrwxrwxrwx 1 root root 21 Oct  5 13:13 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm  [root@localhost ~]# yum -y install console-bridge console-bridge-devel [root@localhost ~]# rpm -ivh bridge-utils-1.5-9.el7.x86_64.rpm  //查看网桥信息 [root@localhost ~]# brctl show bridge name     bridge id               STP enabled     interfaces br0             8000.000c29503472       no              ens33 virbr0          8000.525400e3d6e3       yes             virbr0-nic 

KVM管理界面安装

Kvm的web界面是由webvirtmgr程序提供的

//安装依赖包 [root@localhost ~]# yum -y install git python2-pip supervisor nginx python2-devel [root@localhost ~]# wget http://mirror.centos.org/centos/7/os/x86_64/Packages/libxml2-python-2.9.1-6.el7.5.x86_64.rpm [root@localhost ~]# wget https://download-ib01.fedoraproject.org/pub/epel/7/x86_64/Packages/p/python-websockify-0.6.0-2.el7.noarch.rpm [root@localhost ~]# rpm -ivh --nodeps libxml2-python-2.9.1-6.el7.5.x86_64.rpm [root@localhost ~]# rpm -ivh --nodeps python-websockify-0.6.0-2.el7.noarch.rpm  //升级pip [root@localhost ~]# pip2 install --upgrade pip [root@localhost ~]# pip -V pip 20.3.4 from /usr/lib/python2.7/site-packages/pip (python 2.7)  //从github上下载webvirtmgr代码 [root@localhost ~]# cd /usr/local/src/ [root@localhost src]# git clone http://github.com/retspen/webvirtmgr.git [root@localhost src]# cd webvirtmgr/ [root@localhost webvirtmgr]# ls MANIFEST.in  conf     deploy                images      locale     requirements.txt  servers   templates README.rst   console  dev-requirements.txt  instance    manage.py  secrets           setup.py  vrtManager Vagrantfile  create   hostdetail            interfaces  networks   serverlog         storages  webvirtmgr  //安装webvirtmgr [root@localhost webvirtmgr]# pip install -r requirements.txt  //检查sqlite3是否安装 [root@localhost webvirtmgr]# python3 Python 3.6.8 (default, Jan 19 2022, 23:28:49)  [GCC 8.5.0 20210514 (Red Hat 8.5.0-7)] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import sqlite3 >>> exit()  //初始化账号信息 [root@localhost webvirtmgr]# python2 manage.py syncdb WARNING:root:No local_settings file found. Creating tables ... Creating table auth_permission Creating table auth_group_permissions Creating table auth_group Creating table auth_user_groups Creating table auth_user_user_permissions Creating table auth_user Creating table django_content_type Creating table django_session Creating table django_site Creating table servers_compute Creating table instance_instance 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 Username (leave blank to use 'root'): root Email address: zxr@qq.com Password:  Password (again):  Superuser created successfully. Installing custom SQL ... Installing indexes ... Installed 6 object(s) from 1 fixture(s)  //拷贝web网页到指定目录 [root@localhost ~]# mkdir /var/www/ [root@localhost ~]# cp -r /usr/local/src/webvirtmgr/ /var/www/ [root@localhost ~]# chown -R nginx.nginx /var/www/webvirtmgr/  //生成一对公钥与私钥,由于这里webvirtmgr和kvm服务部署在同一台主机中,所以这里本地信任。如果kvm部署在其他机器上的时候,那么就需要把公钥发送到kvm主机中 [root@localhost ~]# ssh-keygen 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:hI+oL9bkdc32wE84GpniOpfme58q852du72lauPhEcc root@localhost.localdomain The key's randomart image is: +---[RSA 3072]----+ |                 | |       .         | |      . .        | |     . +     .   | |    . . S* .. E  | |   .. o = O .o   | |  .+ o + + *o   .| |  o.+ B o. === o | | . .o*o*oo=oO=+. | +----[SHA256]-----+ [root@localhost ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub root@192.168.111.141 /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub" The authenticity of host '192.168.111.141 (192.168.111.141)' can't be established. ECDSA key fingerprint is SHA256:+KjoLZnhr7A3Jz2DNbF6JHSkb/6pBZPVizet4RohrS0. 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@192.168.111.141's password:   Number of key(s) added: 1  Now try logging into the machine, with:   "ssh 'root@192.168.111.141'" and check to make sure that only the key(s) you wanted were added.  //配置端口转发 [root@localhost ~]# ssh 192.168.111.141 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60  //查看端口 [root@localhost ~]# ss -anlt 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 ~]# cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf.bak [root@localhost ~]# vim /etc/nginx/nginx.conf //在server参数中进行修改 删除listen       [::]:80;行 参数server_name行改成server_name  localhost; 删除root         /usr/share/nginx/html;行 server {         listen       80 ;         server_name  localhost; //在include /etc/nginx/default.d/*.conf;行下添加  location / {                 root    html;                 index   index.html index.htm;         }  //配置nginx虚拟主机 [root@localhost ~]# vim /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绑定本机的8000端口 [root@localhost ~]# grep "bind"  /var/www/webvirtmgr/conf/gunicorn.conf.py # bind - The socket to bind. bind = '127.0.0.1:8000'  //重启nginx服务,查看端口是否开启 [root@localhost ~]# systemctl restart nginx.service  [root@localhost ~]# ss -anlt State   Recv-Q  Send-Q   Local Address:Port   Peer Address:Port  Process   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            0.0.0.0:111         0.0.0.0:*               LISTEN  0       128            0.0.0.0:80          0.0.0.0:*               LISTEN  0       128            0.0.0.0:22          0.0.0.0:*               LISTEN  0       128              [::1]:6080           [::]:*               LISTEN  0       128              [::1]:8000           [::]:*               LISTEN  0       128               [::]:111            [::]:*               LISTEN  0       128               [::]:22             [::]:*     //设置supervisor [root@localhost ~]# vim /etc/supervisord.conf 在最后一行添加 [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@kvm ~]# systemctl enable --now supervisord  //配置nginx用户  //验证基于密钥认证是否成功  //修改nginx配置文件  //对系统参数进行设置  //重启服务,重读文件   //安装novnc,并通过novnc_server启动一个vnc      

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