KVM安装及简单使用
基于内核的虚拟机 Kernel-based Virtual Machine（KVM）是一种内建于 Linux® 中的开源虚拟化技术。使主机计算机能够运行多个隔离的虚拟环境，即虚拟客户机或虚拟机（VM）。
环境准备
检查该服务器是否支持虚拟化，尤其是cpu，这里如果没有输出则需要进入BIOS去调整cpu的虚拟化，具体百度即可，虚拟机则很方便在虚拟机设置里即可打开cpu虚拟化
egrep -o 'vmx | svm' /proc/cpuinfo | wc -l关闭防火墙和selinux
# systemctl stop firewalld
# systemctl disable firewalld
# setenforce 0
# vim /etc/selinux/config
# 修改以下内容
SELINUX=disabled安装KVM
# yum install -y kvm virt-* libvirt bridge-utils qemu-img查看kvm是否被加载到内核
# lsmod | grep kvm网络设置
和VMware一样有桥接模式和nat模式
桥接模式
就是添加了新网卡br0，将br0绑定到ens33上
绑定网卡--以太网通道--聚合链路--桥接网络
[root@localhost ~]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# vim ifcfg-ens33
# 更改，把原有ip删了
ONBOOT=none
BRIDGE=br0
BOOTPROTO=dhcp
[root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@localhost network-scripts]# vim ifcfg-br0
# 更改
TYPE=Bridge
BOOTPROTO=none
NAME=br0
DEVICE=br0
ONBOOT=yes
# 添加：
IPADDR=192.168.1.1
NETMASK=255.255.255.0
# 删除
BRIDGE=br0
# 重启网卡
systemctl restart network这样在查看网络设备时，会多处一块br0设备
查看虚拟网络设备brctl show
NAT模式
启动libvirtd服务后，自会生成一个virbr0的虚拟网络设备
# systemctl start libvirtd
# systemctl disable ilbvirtd
# systemctl startmessagebus如果启动libvirtd报错如下
libvirtd: relocation error: libvirtd: ... version ... libdevmapper.so.1.02 [失败]只需要更新对应软件包即可
# yum upgrade device-mapper-libs然后查看虚拟设备
# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.52540037d52e yes virbr0-nic安装虚拟机
创建虚拟机磁盘镜像文件
执行此命令会在指定路径下生成一个文件，大小为指定大小，指定的大小须在物理机容量范围
# qemu-img create -f qcow2 -o preallocation=metadata /root/test.qcow2 20G将使用该磁盘镜像文件来安装虚拟机
执行安装虚拟机
图形化安装
需要连接vnc等图形界面工具
# virt-install --name test_1 --ram 8192 --vcpus 4 \
-f /root/test_1.qcow2 --os-type linux \
--os-variant rhel7 --network bridge=virbr0 \
--cdrom CentOS-7-x86_64-DVD-1810.iso \
--graphics vnc,listen=0.0.0.0,port=5920
# 输出如下
WARNING Graphics requested but DISPLAY is not set. Not running virt-viewer.
WARNING No console to launch for the guest, defaulting to --wait -1
Starting install...
Domain installation still in progress. Waiting for installation to complete.
# 这个位置需要连接vnc，进行选择语言/硬盘等界面的操作需要准备一个vnc工具连接宿主机的ip和上面设置的port，即可进行图形化界面的安装
命令行安装
命令行安装的结果是我把电脑放置了一夜然后才看到成功的
使用以下会进入命令行的系统安装
# virt-install --virt-type=kvm --name test --vcpus=2 --memory=8192 \
--location=/root/CentOS-7-x86_64-DVD-1810.iso \
--disk path=/root/test.qcow2,size=4,format=qcow2 \
--network bridge=virbr0 --graphics none \
--extra-args='console=ttyS0' --force进入命令行选择
需要选择序号后面带感叹号的进行设置，下面的3&4不用进行设置
时区设置
===================================================================================================
===================================================================================================
Installation
1) [x] Language settings 2) [!] Time settings
(English (United States)) (Timezone is not set.)
3) [!] Installation source 4) [!] Software selection
(Processing...) (Processing...)
5) [!] Installation Destination 6) [x] Kdump
(No disks selected) (Kdump is enabled)
7) [ ] Network configuration 8) [!] Root password
(Not connected) (Password is not set.)
9) [!] User creation
(No user will be created)
Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 2
# 选择2设置时区
===================================================================================================
===================================================================================================
Time settings
Timezone: not set
NTP servers:not configured
1) Set timezone
2) Configure NTP servers
Please make your choice from above ['q' to quit | 'c' to continue |'r' to refresh]: 1 # 选择设置时区，如果有NTP服务器则选择2
===================================================================================================
===================================================================================================
Timezone settings
Available regions
1) Europe 6) Pacific 10) Arctic
2) Asia 7) Australia 11) US
3) America 8) Atlantic 12) Etc
4) Africa 9) Indian
5) Antarctica
Please select the timezone.
Use numbers or type names directly [b to region list, q to quit]: 2 # 选择亚洲时区
===================================================================================================
===================================================================================================
Timezone settings
Available timezones in region Asia
1) Aden 29) Hong_Kong 56) Pontianak
2) Almaty 30) Hovd 57) Pyongyang
3) Amman 31) Irkutsk 58) Qatar
4) Anadyr 32) Jakarta 59) Qyzylorda
5) Aqtau 33) Jayapura 60) Riyadh
6) Aqtobe 34) Jerusalem 61) Sakhalin
7) Ashgabat 35) Kabul 62) Samarkand
8) Atyrau 36) Kamchatka 63) Seoul
9) Baghdad 37) Karachi 64) Shanghai
10) Bahrain 38) Kathmandu 65) Singapore
11) Baku 39) Khandyga 66) Srednekolymsk
12) Bangkok 40) Kolkata 67) Taipei
13) Barnaul 41) Krasnoyarsk 68) Tashkent
14) Beirut 42) Kuala_Lumpur 69) Tbilisi
15) Bishkek 43) Kuching 70) Tehran
16) Brunei 44) Kuwait 71) Thimphu
17) Chita 45) Macau 72) Tokyo
18) Choibalsan 46) Magadan 73) Tomsk
19) Colombo 47) Makassar 74) Ulaanbaatar
20) Damascus 48) Manila 75) Urumqi
21) Dhaka 49) Muscat 76) Ust-Nera
22) Dili 50) Nicosia 77) Vientiane
23) Dubai 51) Novokuznetsk 78) Vladivostok
24) Dushanbe 52) Novosibirsk 79) Yakutsk
25) Famagusta 53) Omsk 80) Yangon
26) Gaza 54) Oral 81) Yekaterinburg
27) Hebron 55) Phnom_Penh 82) Yerevan
28) Ho_Chi_Minh
Please select the timezone.
Use numbers or type names directly [b to region list, q to quit]: 64
# 选择64为上海时区，然后会自动退回到设置界面硬盘分区
===================================================================================================
===================================================================================================
Installation
1) [x] Language settings 2) [x] Time settings
(English (United States)) (Asia/Shanghai timezone)
3) [!] Installation source 4) [!] Software selection
(Processing...) (Processing...)
5) [!] Installation Destination 6) [x] Kdump
(No disks selected) (Kdump is enabled)
7) [ ] Network configuration 8) [!] Root password
(Not connected) (Password is not set.)
9) [!] User creation
(No user will be created)
Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 5
# 选择5，进行硬盘选择分区
===================================================================================================
===================================================================================================
Probing storage...
Installation Destination
[x] 1) : 20 GiB (vda)
1 disk selected; 20 GiB capacity; 20 GiB free ...
Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c
# 因为只有一个20G的qcow2文件，所以只有一块虚拟硬盘，c继续
===================================================================================================
===================================================================================================
Autopartitioning Options
[ ] 1) Replace Existing Linux system(s)
[x] 2) Use All Space
[ ] 3) Use Free Space
Installation requires partitioning of your hard drive. Select what space to use
for the install target.
Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: c
# 选择2或者c，使用所有硬盘空间
===================================================================================================
===================================================================================================
Partition Scheme Options
[ ] 1) Standard Partition
[ ] 2) Btrfs
[x] 3) LVM
[ ] 4) LVM Thin Provisioning
Select a partition scheme configuration.
Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: 3
# 选择3，使用LVM的方式进行分区，看情况定即可，然后选择c继续设置root密码
===================================================================================================
===================================================================================================
Installation
1) [x] Language settings 2) [x] Time settings
(English (United States)) (Asia/Shanghai timezone)
3) [x] Installation source 4) [x] Software selection
(Local media) (Minimal Install)
5) [x] Installation Destination 6) [x] Kdump
(Automatic partitioning (Kdump is enabled)
selected) 8) [!] Root password
7) [ ] Network configuration (Password is not set.)
(Not connected)
9) [!] User creation
(No user will be created)
Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 8
# 选择8进行设置密码
===================================================================================================
===================================================================================================
Please select new root password. You will have to type it twice.
Password: # 输入密码
Password (confirm): # 再次输入确认密码
===================================================================================================
===================================================================================================
Question
The password you have provided is weak: The password fails the dictionary check
- it is too simplistic/systematic.
Would you like to use it anyway?
Please respond 'yes' or 'no': yes # 输入yes，确认使用这样的密码，复杂性要求够了就不会出现这一步开始安装
================================================================================
================================================================================
Installation
1) [x] Language settings 2) [x] Time settings
(English (United States)) (Asia/Shanghai timezone)
(Local media) (Minimal Install)
5) [x] Installation Destination 6) [x] Kdump
(Automatic partitioning (Kdump is enabled)
selected) 8) [x] Root password
7) [ ] Network configuration (Password is set.)
(Not connected)
9) [ ] User creation
(No user will be created)
Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: b
# 开始安装开始安装后和正常服务器开机是一样的，这一步会卡很长时间
........
Installing iwl100-firmware (291/306)
Installing iwl2030-firmware (292/306)
Installing iwl5000-firmware (293/306)
Installing iwl6000g2b-firmware (294/306)
Installing iwl5150-firmware (295/306)
Installing iwl7260-firmware (296/306)
Installing iwl3160-firmware (297/306)
Installing iwl105-firmware (298/306)
Installing iwl3945-firmware (299/306)
Installing iwl7265-firmware (300/306)
Installing ivtv-firmware (301/306)
Installing iwl6050-firmware (302/306)
Installing iwl2000-firmware (303/306)
Installing iwl6000g2a-firmware (304/306)
Installing iwl6000-firmware (305/306)
Installing iwl135-firmware (306/306)
Performing post-installation setup tasks
[anaconda] 1:main* 2:shell 3:log 4:storage-lo> Switch tab: Alt+Tab | Help: F1 就这个界面一直持续了一夜，当我想要放弃的时候（ctrl+c），突然好了，出现了以下内容，以下内容都是我多次按ctrl+c出来的。
也可以尝试在以上阻塞的地方一开始就按ctrl+c
.....
Installing iwl135-firmware (306/306)
Performing post-installation setup tasks
^CInstalling boot loader
.
Performing post-installation setup tasks
.
Configuring installed system
^C.
Writing network configuration
.
Creating users
.
Configuring addons
.
Generating initramfs
^C.
Running post-installation scripts
.
Use of this product is subject to the license agreement found at /usr/share/centos-release/EULA
Installation complete. Press return to quit
[anaconda] 1:main* 2:shell 3:log 4:storage-lo> Switch tab: Alt+Tab | Help: F1 然后这个位置回车，就会重启VM
设置开机自启VM
# virsh autostart VM-NAME(虚拟机名) // 开机自启
# virsh autostart --disable VM-NAME(虚拟机名) // 开机不自启 宿主机查看VM_IP
我是根据图形化安装成功的，所以在安装完成重启之后，还是通过vnc连接到了，之后就和正常的服务器一样的网络设置，因为没有IP，我直接使用dhcp获取了kvm的122网段的默认ip，设置与宿主机的ssh即可方便登录
通过宿主机查看ip
# virsh edit VM-NAME
在这个编辑的文件中找到mac地址，通过mac地址查看ip
# arp -a | grep -i 52:54:00:d7:e6:bc
? (192.168.122.213) at 52:54:00:d7:e6:bc [ether] on virbr0博客内容遵循 署名-非商业性使用-相同方式共享 4.0 国际 (CC BY-NC-SA 4.0) 协议
