KVM安装配置1.安装epel包:
[root@node124mnt]# rpm -Uvh http://ftp.linux.ncsu.edu/pub/epel/6/i386/epel-release-6-8.noarch.rpm
yum makecache
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查看CPU是否支持虚拟化：(打开vmware CPU虚拟化功能)
vmx似乎是intel的虚拟技术代名词
svm似乎是amd的虚拟技术代名词
如果你在将kvm的模块加载的时候出现如下现象
#cat /proc/cpuinfo | egrep -c '(vmx|svm)'
[root@node123 ~]# cat /proc/cpuinfo | egrep -c'(vmx|svm)'
2
0 表示不支持，大于1 表示支持。
#modprobe kvm-intel
正常情况下：
[root@node124 opt]# lsmod | grep kvm*
kvm_intel 55624 0
kvm 341551 1 kvm_intel
不支持的情况：
FATAL: Error inserting kvm_intel(/lib/modules/2.6.17-10-generic/extra/kvm-intel.ko): Operation not supported
那么只有两个可能
1:CPU不支持 (是否支持要 more/proc/cpuinfo,找找vmx或者svm)
2:Bios给关了.(去打开吧,如果看到了)
3.在vmx文件中没有开启vhv.enable = "TRUE"
在workstation上实现嵌套虚拟化，需要编辑虚拟机的主机名.vmx 文件，
在文件中添加或修改:
vhv.enable = "TRUE"
VMWARE调整如下：
参考KB如下（Additional Information部分）
http://kb.vmware.com/kb/2034803
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2,安装虚拟化工具：
yum install qemu-kvm qemu-kvm-tools virt-managerlibvirt
qemu-kvm qemu-kvm-tools:qemu工具用于管理KVM
virt-manager:创建虚拟机
libvirt: 用于创建虚拟机与管理
3.创建虚拟机硬盘：
#qemu-img create -f raw /opt/CentOS-6.7_x86_64.raw 5G
查看创建的硬盘：
#file /opt/CentOS-6.7_x86_64.raw
#qemu-img info/opt/CentOS-6.7_x86_64.raw
4.创建光盘镜像：
#dd if=/dev/cdrom of=/opt/CentOS-6.7-x86_64.iso
5.创建虚拟机
[root@node124 opt]# virt-install--virt-type=kvm --name CentOS-6.7-x86_64 --ram 512--cdrom=/opt/CentOS-6.7_x86_64.iso --disk path=/opt/CentOS-6.7_x86_64.raw--network network=default --graphics vnc,listen=0.0.0.0 --noautoconsole--os-type=linux --os-variant=rhel6
Starting install...
Creating domain... | 0 B 00:00
Domain installation still in progress. You canreconnect to
the console to complete the installation process.
6.通过VNC安装虚拟机:
软件：tightvnc2.7.10.exe ip地址为宿主机网卡接口IP
7.查看已安装虚拟机列表：
#virsh list --all
[root@node124 opt]# virsh list --all
Id Name State
----------------------------------------------------
2 CentOS-6.7-x86_64 running
8.如果名称被定义，则通过以下命令取消定义：
#virsh undefine CentOS-6.7-x86_64
9.查看连接状态(查看VNC端口5900)
[root@node124 opt]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:55687 0.0.0.0:* LISTEN 1556/rpc.statd
tcp 0 0 0.0.0.0:5900 0.0.0.0:* LISTEN 2934/qemu-kvm
10.查看kvm进程
#ps aux | grep kvm
qemu 293443.8 28.9 2128088 552808 ? Sl 22:28 2:10 /usr/libexec/qemu-kvm -name CentOS-6.7-x86_64 -S -M rhel6.6.0-enable-kvm -m 512 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid326e3810-fd4d-5012-f6f7-cff369870ccd -nodefconfig -nodefaults -chardevsocket,id=charmonitor,path=/var/lib/libvirt/qemu/CentOS-6.7-x86_64.monitor,server,nowait-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-reboot-no-shutdown -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x4.0x7 -deviceich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x4 -deviceich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x4.0x1 -deviceich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x4.0x2 -drivefile=/opt/CentOS-6.7_x86_64.raw,if=none,id=drive-virtio-disk0,format=raw,cache=none-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2-drivefile=/opt/CentOS-6.7_x86_64.iso,if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw-device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,bootindex=1-netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23 -devicevirtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:37:e2:fa,bus=pci.0,addr=0x3-chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0-device usb-tablet,id=input0 -vnc 0.0.0.0:0 -vga cirrus -devicevirtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -msg timestamp=on
启动已停止的虚拟机：
[root@node124 ~]# virsh list
Id Name State
----------------------------------------------------
[root@node124 opt]# virsh list --all
Id Name State
----------------------------------------------------
- CentOS-6.7-x86_64 shut off
[root@node124 opt]# virsh start CentOS-6.7-x86_64
Domain CentOS-6.7-x86_64 started
查看已安装虚拟机的XML配置文件：路径在：/etc/libvirt/qemu
[root@node124 qemu]# ls
CentOS-6.7-x86_64.xml networks
[root@node124 qemu]# pwd
/etc/libvirt/qemu
[root@node124 qemu]# cat CentOS-6.7-x86_64.xml
<!--
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO ITARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xmlconfiguration should be made using:
virsh editCentOS-6.7-x86_64
or other application using the libvirt API.
-->
默认修改这个文件将不会在虚拟机生效，不管重启或不重启
但可以通过以下的方式来使这个配置文件修改后就生效：
1.cp CentOS-6.7-x86_64.xml /opt/CentOS-6.7-x86_64.xml
2.virsh undefine CentOS-6.7-x86_64
3.virsh define /opt/CentOS-6.7-x86_64.xml #相当于重新创建一台虚拟机,kvm是通过.xml来管理虚拟机的
最好通过virsh edit CentOS-6.7-x86_64 来编辑虚拟机，前题是虚拟机是关闭状态
.xml文件是重新的虚拟机文件，如果这个文件不存在，虚拟机也就不存在了
内存优化：
[root@node124 qemu]# cat/sys/kernel/mm/transparent_hugepage/enabled
[always] madvise never
[root@node124 qemu]# ps aux | grep ksm
root 47 0.0 0.0 0 0 ? SN 22:02 0:00 [ksmd]
root 1914 0.0 0.0 108208 776 ? S 22:02 0:00 /bin/bash/usr/sbin/ksmtuned
root 4029 0.0 0.0 103312 852 pts/2 S+ 23:28 0:00 grep ksm
虚拟机的大小不能超过实体机的所有资源的总和
