Xen虚拟机模版制作

Posted 2020-10-26

制作模版

• windows

  1. 准备虚拟机
     安装配置好一个用来制作模版的虚拟机

  2. 导出windows的mbr到文件(仅适用于mbr分区表的windows操作系统),基于lvm(基于文件需要使用loop设备)

     dd if=/dev/mapper/vg_lv_name of=/path/to/windows_tpl.mbr count=1 bs=512

  3. 生成模板磁盘的分区设备

     kpartx -av /dev/mapper/vg_lv_name

  4.复制模板数据到文件(或分区)

  ntfsclone -r -O  windows_tpl.img /dev/mapper/vg_lv_namep1

  5.删除分区设备

  kpartx -dv /dev/mapper/vg_lv_name

  • linux(仅适用于半虚拟化)
    1.打包整个系统

    tar cpzf test.tar.gz --exclude=/os_tpl.tar.gz /

  2.建立虚拟磁盘

  dd if=/dev/zero of=os_tpl.img bs=1 count=1 seek=10G
  mkfs.ext4 test.img
  mount -o loop test.img /mnt

  3.释放系统文件到虚拟磁盘

  tar -zxSf os_tpl.tar.gz -C /mnt/os_tpl

  4.挂载系统所需目录(无此目录可创建)，然后chroot

  sudo mkdir -p /mnt/os_tpl/{proc,sys,dev,dev/pts}
  
  sudo mount -t proc proc /mnt/os_tpl/proc/
  sudo mount -t sysfs sys /mnt/os_tpl/sys/
  sudo mount -o bind /dev /mnt/os_tpl/dev/
  sudo mount -o bind /dev/pts /mnt/os_tpl/dev/pts/
  sudo chroot /mnt/os_tpl

  5.chroot后更新系统并安装linux-virtual内核,当然,不要忘了更新 grub(centos同理)

  apt-get update & apt-get upgrade
  apt-get install linux-virtual
  apt-get purge grub2 grub-pc
  apt-get install grub
  update-grub

  6.换了内核后还需要更新和配置几个系统文件,menu.lst,fstab,hvc0.conf,以便新内核能在 Xen 虚拟环境里正常启动

  # vi /boot/grub/menu.lst
  Kernel command line: root=/dev/xvda1 xencons=tty console=tty1 console=hvc0 nosep nodevfs ramdisk_size=32768 ip_conntrack.hashsize=8192 nf_conntrack.hashsize=8192 ro devtmpfs.mount=1 

  # vi /etc/fstab
  /dev/xvda1      /           ext4    noatime,errors=remount-ro       0 1
  /dev/xvda2      none        swap    sw                              0 0
  tmpfs           /dev/shm    tmpfs   nodev,nosuid,noexec,mode=1777   0 0
  devpts          /dev/pts    devpts  gid=5,mode=620                  0 0
  sysfs           /sys        sysfs   defaults                        0 0
  /proc           /proc       proc    defaults                        0 0
  /dev/xvdb       /home       ext4    noatime,errors=remount-ro       0 1

  # vi /etc/init/hvc0.conf
  # hvc0 - getty
  #
  # This service maintains a getty on hvc0 from the point the system is
  # started until it is shut down again.
  
  start on stopped rc RUNLEVEL=[2345]
  stop on runlevel [!2345]
  
  respawn
  exec /sbin/getty -8 38400 hvc0

  7.退出chroot并逆顺序卸载刚才挂载的目录

  umount /mnt/os_tpl/proc/
  umount /mnt/os_tpl/sys/
  umount /mnt/os_tpl/dev/pts/
  umount /mnt/os_tpl/dev/
  umount /mnt/os_tpl

  # xl create test.cfg

创建虚拟机

• windows
  1.创建磁盘/磁盘镜像

  lvcreate -L 20G -n xxx vg

  2.从模版mbr恢复mbr到磁盘

  dd if=2003_tpl.mbr of=/dev/mapper/vg_lv_name  count=1 bs=512

  3.创建分区设备

  kpartx -av /dev/mapper/vg_lv_name

  4.复制模版数据到分区设备

  ntfsclone -r -O /dev/mapper/vg_lv_namep1 windows_tpl.img

  4.根据需要在分区设备执行resize

  ntfsresize -f -v /dev/mapper/vg_lv_namep1

  5.删除分区设备

  kpartx -dv /dev/mapper/vg_lv_name

• Linux
  1.建立虚拟磁盘

  dd if=/dev/zero of=test.img bs=1 count=1 seek=10G

  2.格式化虚拟磁盘

  mkfs.ext4 test.img

  3.挂载虚拟磁盘

  mount -o loop test.img /mnt

  4.释放模版文件到目标位置

  tar -zxSf test.tar.gz -C /mnt/

创建Xen虚拟机配置文件,用 xl create 启动虚拟机

# vi /etc/xen/test.cfg
bootloader = "pygrub"
root = "/dev/xvda ro"
name = "test"
vcpus = "1"
memory = "2048"
disk = [ "file:/root/test.img,xvda,w","file:/root/test.swp,xvdb,w" ]
vif = [ "bridge=xenbr0" ]