CentOS6.4 X86_64 kvm+PXE备忘

Install 安装

1 2 3 4 5

# yum install qemu-kvm qemu-img # 使用kvm至少要安装的包，一个提供用户级别kvm模拟器，一个提供磁盘镜像的管理 # 安装虚拟化管理的相关工具 # yum install virt-manager libvirt \ libvirt-python python-virtinst libvirt-client

也可以yum groupinstall虚拟化组件，具体可参考Redhat官方文档

• KVM 管理工具
  • kvm 内核模块 <- qemu 管理工具 (可用性低)
  • qemu 是开源虚拟化软件, 虚拟不同 CPU 架构, 可以 x86 虚拟 power cpu
  • libvirt, virsh, virt-manager (redhat 的辅助工具)
  • libvirt api 提供管理接口工具
  • virt-manager 调用 libvirt 工具

• ibvirt接口
  • virsh 命令行工具
  • virt-manager 图形工具
  • RHEV-M (redhat专用收费软件)

• 支持三种虚拟设备
  • Emulated software devices 仿真设备 -> 南北桥, USB, PS/2 ISA PCI
  • Para-virtualized devices -> 时钟, 网络, 串口
  • Physically shared devices –> 光纤设备

安装完之后就可以启动kvm了

1	# /etc/init.d/libvirtd start

桥接网络

1	# yum install bridge-utils -y

桥接实例:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

# cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 TYPE=Ethernet ONBOOT=yes NAME="System eth0" BRIDGE="br0" # cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE="br0" TYPE="Bridge" # 注意大小写 BOOTPROTO="static" IPADDR=192.168.80.131 NETMASK=255.255.255.0 GATEWAY=192.168.80.2 ONBOOT="yes" DELAY=0

具体可参考: CentOS / Redhat: KVM Bridged Network Configuration

构建无人值守，实现KVM PXE安装

安装相关软件

1	# yum install tftp-server syslinux dhcp vsftpd -y

dhcp

dhcp example:

dhcp

1 2 3 4 5 6 7 8 9

# cat /etc/dhcp/dhcpd.conf subnet 192.168.80.0 netmask 255.255.255.0 { range 192.168.80.10 192.168.80.100; default-lease-time 600; max-lease-time 7200; next-server 192.168.80.131; # PXE Server地址 filename "pxelinux.0"; # 引导文件名 } # /etc/init.d/dhcpd restart

tftp

tftp example:

tftp

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

# cat /etc/xinetd.d/tftp service tftp { socket_type = dgram protocol = udp wait = yes user = root server = /usr/sbin/in.tftpd server_args = -s /var/lib/tftpboot disable = no # 默认yes，改为no即可 per_source = 11 cps = 100 2 flags = IPv4 } # /etc/init.d/xinetd restart

vsftpd

新建/var/ftp/centos目录，把CentOS光盘镜像挂载至/var/ftp/centos下

1 2 3

# mkdir /var/ftp/centos # mount /dev/cdrom /var/ftp/centos # 挂载镜像使用-o loop # /etc/init.d/vsftpd restart

无人值守

1 2 3 4 5 6

# mkdir /var/lib/tftpboot/CentOS6 # cp /var/ftp/centos/images/pxeboot/{initrd.img,vmlinuz} /var/lib/tftpboot/CentOS6 # cp /var/ftp/centos/isolinux/{boot.msg,vesamenu.c32} /var/lib/tftpboot/ # cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot/ # mkdir /var/ftp/tftpboot/pxelinux.cfg # cp /var/ftp/centos/isolinux/isolinux.cfg /var/lib/tftpboot/pxelinux.cfg/default

tftpboot目录树结构

1 2 3 4 5 6 7 8 9 10 11 12

# tree /var/lib/tftpboot/ /var/lib/tftpboot/ ├── boot.msg ├── CentOS6 │   ├── initrd.img │   └── vmlinuz ├── pxelinux.0 ├── pxelinux.cfg │   └── default └── vesamenu.c32 2 directories, 6 files

pxelinux.cfg/default example:

pxe default

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

# cat /var/lib/tftpboot/pxelinux.cfg/default # default CentOS6_PXE # 默认启动'default CentOS6_PXE'标记的内核 default vesamenu.c32 # 菜单选项 timeout 100 # 单位是1/10s # prompt 1 # 为 '0' 时则不提示'boot: '，将会直接启动 'default' 参数中指定的内容 display boot.msg # 启动时显示 # menu background splash.jpg # 菜单背景等 menu title Welcome to CentOS 6.4! menu color border 0 #ffffffff #00000000 menu color sel 7 #ffffffff #ff000000 menu color title 0 #ffffffff #00000000 menu color tabmsg 0 #ffffffff #00000000 menu color unsel 0 #ffffffff #00000000 menu color hotsel 0 #ff000000 #ffffffff menu color hotkey 7 #ffffffff #ff000000 menu color scrollbar 0 #ffffffff #00000000 label CentOS6_PXE menu label ^PXE Install CentOS KVM kernel /CentOS6/vmlinuz append ks=ftp://192.168.80.131/ks.cfg initrd=/CentOS6/initrd.img label rescue menu label ^Rescue installed system kernel /CentOS6/vmlinuz append initrd=/CentOS6/initrd.img rescue

关于PXE的进一步细节可以参考pxelinux官方文档

ks.cfg example:

ks.cfg

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

# cat /var/ftp/ks.cfg # System authorization information auth --useshadow --enablemd5 # System bootloader configuration bootloader --location=mbr # Clear the Master Boot Record zerombr # Partition clearing information clearpart --all --initlabel # Use text mode install text # Firewall configuration firewall --disabled skipx # Run the Setup Agent on first boot firstboot --disable # System keyboard keyboard us # System language lang en_US # Installation logging level logging --level=info # Use network installation url --url=ftp://192.168.80.131/centos # Network information network --bootproto=dhcp --device=eth0 --onboot=on # Reboot after installation reboot #Root password rootpw --iscrypted $1$duSkJ1$1P5qGnqUGn3S1MTTFiPJY. # SELinux configuration selinux --disabled # System timezone timezone Asia/Shanghai # Install OS instead of upgrade install # Disk partitioning information part /boot --asprimary --bytes-per-inode=4096 --fstype="ext3" --size=100 part / --bytes-per-inode=4096 --fstype="ext3" --size=5000 part swap --bytes-per-inode=4096 --fstype="swap" --size=512 %packages --nobase @core @Development tools acpid # 如果不安装acpid服务，virsh shutdown virtual_name 命令会失效 vim wget lsof %end

如果最小化安装则软件包选择如下：

Minimal install

1 2	%packages --nobase @core

关于kickstart的更进一步了解可参考红帽官档Kickstart Options Installing guest virtual machines with PXE

PXE 安装KVM虚拟机

如果要开启–graphics vnc选项，则需要修改vnc监听端口，默认监听的是127.0.0.1，修改为0.0.0.0即可

1 2 3

# grep '^vnc_listen' /etc/libvirt/qemu.conf vnc_listen = "0.0.0.0" # /etc/init.d/libvirtd restart

man手册关于vnc端口介绍摘录：

Address to listen on for VNC/Spice connections. Default is typically 127.0.0.1   
(localhost only), but some hypervisors allow changing this globally     
(for example, the qemu driver default can be changed   in /etc/libvirt/qemu.conf).   
Use 0.0.0.0 to allow access from other machines. This is use by ’vnc’ and ’spice.  

安装实例：

通过location方式结合Kickstart安装

• –extra-args指定ks相关选项，并且指定console类型使得virsh console可以连接操作，也可指定客户机IP、网关、DNS等，无需DHCP：

1 2 3 4

# virt-install --name centos --ram=1024 --vcpus=1 --os-type=linux --os-variant=rhel6 \ --network bridge:br0 --disk path=/var/lib/libvirt/images/centos6-machine1.img,size=10 \ --location ftp://192.168.80.131/centos/ --extra-args "ks=ftp://192.168.80.131/ks.cfg \ ksdevice=eth0 ip=192.168.80.150 netmask=255.255.255.0 console=ttyS0"

PXE方式安装

1 2 3 4

# virt-install --connect qemu:///system --network=bridge:br0 \ --pxe --name rhel6-machine1 --ram=1024 --vcpus=1 \ --os-type=linux --os-variant=rhel6 --disk \ path=/var/lib/libvirt/images/rhel6-machine1.img,size=10

注意: 如果需要指定console，–pxe是不支持–extra-args额外选项的，所以需要在pxe default 文件添加相关内容[SERIAL和console]，如下example

1 2 3 4 5

SERIAL 0 115200 label CentOS6_PXE menu label ^PXE Install CentOS KVM kernel /CentOS6/vmlinuz append ks=ftp://192.168.80.131/ks.cfg initrd=/CentOS6/initrd.img console=tty0 console=ttyS0,115200

本地安装：

1 2 3

# virt-install --name centos --ram=1024 --vcpus=1 --os-type=linux \ --os-variant=rhel6 --location /mnt/ --network bridge:br0 \ --disk path=/var/lib/libvirt/images/rhel6.img,size=10 --extra-args "console=ttyS0"

关于KVM的Guest安装方式，virt-install man手册中也有很多实例，这里不一一介绍。

开启–graphics vnc选项可在Windows下下载vncviewer客户端，输入对应IP和端口即可[ 笔者个人还是习惯通过console连接安装，不开启vnc选项 ]，如下

查看对应端口

1 2 3

# netstat -tulnp | grep kvm tcp 0 0 0.0.0.0:5900 0.0.0.0:* LISTEN 55762/qemu-kvm tcp 0 0 0.0.0.0:5901 0.0.0.0:* LISTEN 56656/qemu-kvm

连接对应端口

连接之后,就可以正常安装了

virsh 操作命令

这里只介绍一些常用的virsh使用方法，具体的命令可以参看virsh的man手册介绍或者参考红帽官方文档Managing guests with virsh

默认只输入virsh命令会进入virsh的终端：如下，help可以获取命令帮助

1 2 3 4 5 6 7

# virsh Welcome to virsh, the virtualization interactive terminal. Type: 'help' for help with commands 'quit' to quit virsh #

virsh简单操作

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

virsh # list # 显示运行或者暂停的Guest Id Name State ---------------------------------------------------- 28 centos6_1 running virsh # list --all # 显示所有的Guest，包括状态为shut off的 Id Name State ---------------------------------------------------- 28 centos6_1 running - centos shut off virsh # console centos6_1 # console方式连接Guest Connected to domain centos6_1 Escape character is ^] # 使用Ctrl+]即可退出 CentOS release 6.4 (Final) Kernel 2.6.32-358.el6.x86_64 on an x86_64 localhost.localdomain login: virsh # start centos # 开启某个Guest Domain centos started virsh # list Id Name State ---------------------------------------------------- 28 centos6_1 running 32 centos running virsh # shutdown centos # 关闭某个Guest，这里一定要注意，如果Guest没有安装运行acpid服务， # 则此方式失效，可以kill强制关闭，或者console/ssh连接执行关闭 Domain centos is being shutdown

删除某个Guest，一般需要两步走，对于正在运行的Guest则需要先关闭再继续两步走[也可以直接virsh destroy virtual_name], 这里就演示三步：

1 2 3

virsh destroy guest_name virsh undefine guest_name rm -rf guest_img # 删除虚拟存储

挂起主机

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

virsh # list Id Name State ---------------------------------------------------- 28 centos6_1 running virsh # suspend centos6_1 # 挂起主机 Domain centos6_1 suspended virsh # list Id Name State ---------------------------------------------------- 28 centos6_1 paused virsh # resume centos6_1 # 把主机从挂起状态切换至运行状态 Domain centos6_1 resumed virsh # list Id Name State ---------------------------------------------------- 28 centos6_1 running virsh #

virt-clone 克隆Guest

1 2 3 4 5 6 7 8 9 10 11 12 13 14

# virt-clone --connect=qemu:///system --original=centos6_1 \ --name=centos6_2 -f /var/lib/libvirt/images/centos6_2.img ERROR Domain with devices to clone must be paused or shutoff. # virsh suspend centos6_1 Domain centos6_1 suspended # virsh list Id Name State ---------------------------------------------------- 28 centos6_1 paused # virt-clone --connect=qemu:///system --original=centos6_1 \ --name=centos6_2 -f /var/lib/libvirt/images/centos6_2.img Allocating 'centos6_2.img' 1% [- ] 9.0 MB/s | 112 MB 18:44 ETA

参考和拓展资料

• Automate RHEL Based OS Deployments with PXE Boot and Kickstart
• Centos& and serial console login
• kvm virsh console
• KVM 实时迁移
• rhel6 kvm备忘

自己之前的两篇挫文： KVM在线迁移(动态迁移) RHEL6 KVM安装备忘

–EOF–