kvm-2使用qcow2管理KVM虚拟机磁盘 推荐

KVM2-使用qcow2管理KVM虚拟机磁盘
1、创建一个基础镜像文件

[root@server1 images]# pwd /var/lib/libvirt/images //虚拟机默认创建的位置 [root@server1 images]# qemu-img create -f qcow2 rhel6test.img 80G Formatting 'rhel6base.img', fmt=qcow2 size=85899345920 encryption=off cluster_size=65536 [root@server1 images]# vim ~/bin/install-rhel6 [root@server1 images]# cat ~/bin/install-rhel6 #!/bin/bash /usr/sbin/virt-install \ --vnc \ --noautoconsole \ --name=rhel6test \ --ram=1024 \ --arch=x86_64 \ --vcpus=1 \ --os-type=linux \ --os-variant=rhel6 \ --hvm \ --accelerate \ --disk=/var/lib/libvirt/images/rhel6test.img \ -m 52:54:00:00:01:02 \ -w bridge=br0 \ --location=ftp://192.168.3.1/rhel6 \ --extra-args="ks=ftp://192.168.3.1/ks.cfg" [root@server1 images]#

2、安装系统到镜像文件
[root@server1images]# install-rhel6

Startinginstall...
Retrievingfile vmlinuz... | 7.7 MB 00:00 ...
Retrievingfile initrd.img... | 60 MB 00:00 ...
Creatingdomain... | 0 B 00:00
Domaininstallation still in progress. You can reconnect to
theconsole to complete the installation process.
[root@server1images]#
注：详细的install-rhel6文件请参考：http://murongqingqqq.blog.51cto.com/2902694/1396080

3、基于基础镜像文件创建增量镜像文件---克隆机器
[root@server1images]# qemu-img create -b rhel6test.img -f qcow2 rhel6testnode1.img
Formatting'rhel6testnode1.img', fmt=qcow2 size=85899345920 backing_file='rhel6test.img'encryption=off cluster_size=65536
[root@server1images]#

4、导出原始虚拟机的配置文件说明
查看虚拟机rhel6test的配置信息：[root@server1 images]# virsh dumpxml rhel6test
将配置信息作为模板导出：
[root@server1images]# virsh dumpxml rhel6test > /tmp/rhel6testnode1.xml

5、修改配置文件，以满足克隆虚拟机的要求
[root@server1images]# uuidgen
3b69e07e-95a9-48eb-b95d-52507ad864e0
[root@server1images]# vim /tmp/rhel6testnode1.xml //一共修改四处
<name>rhel6testnode1</name>
<uuid>3b69e07e-95a9-48eb-b95d-52507ad864e0</uuid>
<source file='/var/lib/libvirt/images/rhel6testnode1.img'/>
<mac address='52:54:00:00:01:03'/>

6、根据配置文件定义新的克隆虚拟机
[root@server1images]# virsh define /tmp/rhel6testnode1.xml

附：实现自动创建克隆虚拟机的脚本：等同步骤3-6

[root@server1 ~]# vim bin/clone-rhel6 [root@server1 ~]# cat bin/clone-rhel6 #!/bin/bash qemu-img create -b /var/lib/libvirt/images/rhel6test.img -f qcow2 /var/lib/libvirt/images/rhel6testnode1.img virsh dumpxml rhel6test > /tmp/rhel6test.xml sed -i '/<name>rhel6test/s/rhel6test/rhel6testnode1/' /tmp/rhel6test.xml sed -i "/<uuid>/s/<uuid>.\{36\}/<uuid>$(uuidgen)/" /tmp/rhel6test.xml sed -i "/rhel6test\.img/s/rhel6test\.img/rhel6testnode1\.img/" /tmp/rhel6test.xml sed -i "/mac address/s/00'/03'/" /tmp/rhel6test.xml virsh define /tmp/rhel6test.xml

经过优化后的脚本
实现功能：
1，支持判断用户输入的字符判断，可用范围为（1-254）
2，多余输出信息导入到/dev/null中
3，支持输出错误编码$?
4，如果需要修改原虚拟机名，直接修改$BASE_VM的值即可
5，支出输出信息[OK]高亮显示

[root@server1 ~]# cat bin/clone-rhel6.sh #!/bin/bash IMG_DIR=/var/lib/libvirt/images //定义变量，虚拟机文件存放的位置 BASE_VM=rhel6test //定义变量，基础虚拟机的名字 E_NOINPUT=65 //定义输出错误编码 E_NOTNUM=66 E_OUT_OF_RANGE=67 E_VM_EXISTS=68 read -p "please input a vm number(0-254): " NEW_VMNU //交互式输入增量虚拟机的编号 if [ -z $NEW_VMNU ]; then //判断编号是否为空 echo "You must input a number." exit $E_NOINPUT fi if [ $NEW_VMNU != $(echo "$NEW_VMNU*1" | bc) ]; then //判断编号是否为字符 echo "You must input a number." exit $E_NOTNUM fi if [ $NEW_VMNU -lt 1 -o $NEW_VMNU -gt 254 ]; then //判断编号是否超出了1-254范围 echo "You must input a number between 1 and 254" exit $E_OUT_OF_RANGE fi NEW_VM=${BASE_VM}node${NEW_VMNU} //定义增量虚拟机的名字 if [ -e $IMG_DIR/$NEW_VM.img ]; then //判断增量虚拟机编号是否重复 echo "$NEW_VM already exists" exit $E_VM_EXISTS fi echo -en "creating disk image......\t\t" //-en选项，不换行输出，为了连接下面的ok qemu-img create -b $IMG_DIR/$BASE_VM.img -f qcow2 $IMG_DIR/$NEW_VM.img &> /dev/null echo -e "\e[32m[OK]\e[0m" //高亮显示输出内容：[ok] echo //echo后面不接选项和参数，输出空行 virsh dumpxml $BASE_VM > /tmp/$BASE_VM.xml //生成克隆虚拟机XML文件 MAC_ADDR=$(echo "obase=16;$NEW_VMNU" | bc) //定义mac地址后两位数字 sed -i "/<name>$BASE_VM/s/$BASE_VM/$NEW_VM/" /tmp/$BASE_VM.xml //XML文件需要修改的四处 sed -i "/<uuid>/s/<uuid>.\{36\}/<uuid>$(uuidgen)/" /tmp/$BASE_VM.xml sed -i "/$BASE_VM\.img/s/$BASE_VM\.img/$NEW_VM\.img/" /tmp/$BASE_VM.xml sed -i "/mac address/s/00'/$MAC_ADDR'/" /tmp/$BASE_VM.xml virsh define /tmp/$BASE_VM.xml &> /dev/null //定义新的虚拟机 echo "$NEW_VM created successful !!!" [root@server1 ~]# 注：其实核心句子就是绿色字体的四个步骤