KVM学习笔记(二)--虚拟机克隆

时间:2022-03-19 20:48:15

一、KVM创建虚拟机


创建磁盘文件及虚拟机镜像


[root@ckcest04 images]# ll /var/lib/libvirt/images/    #kvm存放虚拟机的路径

[root@kvmaster2 images]# qemu-img create ckcest07.img 30G
Formatting 'ckcest07.img', fmt=raw size=32212254729

[root@kvmaster2 images]# virt-install --name=ckcest07 --ram 2048 --vcpus=2 --disk path=/var/lib/libvirt/images/ckcest07.img,size=150 \
--cdrom /opt/Centos-6.4-x86_64-bin-DVD1.iso --network bridge=br0 --force --autostart

#virt-install 安装虚拟机命令,更多请--help
#--name 虚拟机名字
#--ram 内存
#--vcpus cpu核数
#--disk path 虚拟机路径,大小
#--cdrom iso路径
#--network bridge 桥接到网桥的名字,教程一里的网桥名
#--autostart 自动开启
#然后就是图形界面的安装操作系统步骤,这里不再赘述。


配置操作系统


[root@ckcest07 opt]# sed -i '/^HWADDR/d' /etc/sysconfig/network-scripts/ifcfg-eth0[root@ckcest07 opt]# sed -i '/^UUID/d' /etc/sysconfig/network-scripts/ifcfg-eth0[root@ckcest07 opt]# echo -n > /etc/udev/rules.d/70-persistent-net.rules#上面三条命令是为了用此系统做镜像,再建立虚拟机的时候,可以获得新的mac地址,否则到时候还要重新配置


[root@kvmaster2 images]# virsh list              #虚拟机运行正常
 Id    名称                         状态
----------------------------------------------------
 1     ckcest07                       running


将raw格式转换成qcow2格式


[root@kvmaster2 images]# qemu-img info ckcest07.img
image: ckcest07.img
file format: raw
virtual size: 30G (32212254720 bytes)
disk size: 2.9G

[root@kvmaster2 images]# qemu-img convert -O qcow2 ckcest07.img ckcest07.img.qcow2
[root@kvmaster2 images]# qemu-img info ckcest07.img.qcow2
image: ckcest07.img.qcow2
file format: qcow2
virtual size: 30G (32212254720 bytes)
disk size: 2.3G
cluster_size: 65536

#虚拟机各种磁盘格式介绍:
http://blog.chinaunix.net/uid-14735472-id-4220089.html

根据创建的"基类"镜像,生成新的虚拟机

[root@kvmaster2 images]# qemu-img create -f qcow2 ckcest08.qcow2 -o backing_file=ckcest07.img 150G \
Formatting 'ckcest08.qcow2', fmt=qcow2size=161061273600 backing_file='ckcest07.img' encryption=off cluster_size=65536

#基类镜像是30G大小、派生出来的镜像可以额外使用150G空间。
[root@kvmaster2 images]# qemu-img info ckcest08.qcow2
image: ckcest08.qcow2
file format: qcow2
virtual size: 150G (161061273600 bytes)
disk size: 196K
cluster_size: 65536
backing file: ckcest07.img


挂载额外的磁盘空间


[root@ckcest08 ~]# df -h                                  #根目录只有20G大小
文件系统 容量 已用 可用 已用%% 挂载点
/dev/mapper/vg_ckcest07-LogVol03
20G 2.0G 17G 11% /
tmpfs 939M 0 939M 0% /dev/shm
/dev/vda1 97M 33M 60M 35% /boot
/dev/mapper/vg_ckcest07-LogVol00
9.9G 151M 9.2G 2% /home
/dev/mapper/vg_ckcest07-LogVol02
97M 5.6M 87M 7% /tmp


[root@ckcest08 ~]# fdisk -l #额外的磁盘空间,后面将他挂载到根目录下

Disk /dev/vda: 161.1 GB, 161061273600 bytes
16 heads, 63 sectors/track, 312076 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e1aeb

Device Boot Start End Blocks Id System
/dev/vda1 * 3 206 102400 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2 206 62416 31353856 8e Linux LVM
Partition 2 does not end on cylinder boundary.

#因为磁盘是用了LVM做了逻辑卷,所以先把磁盘放到VG,不了解lvm的朋友可以看下http://www.cnblogs.com/gaojun/archive/2012/08/22/2650229.html

[root@ckcest08 ~]# fdisk /dev/vda #fdisk来创建分区

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): p #显示当前磁盘信息

Disk /dev/vda: 161.1 GB, 161061273600 bytes
16 heads, 63 sectors/track, 312076 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e1aeb

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *           3         206      102400   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2             206       62416    31353856   8e  Linux LVM
Partition 2 does not end on cylinder boundary.

Command (m for help): n #创建一个新的分区
Command action
   e   extended
   p   primary partition (1-4)
p #选择新建分区
Partition number (1-4): 3 #之前有了2个,所以这里是3,回车。
First cylinder (1-312076, default 1): 62417
Last cylinder, +cylinders or +size{K,M,G} (62417-312076, default 312076):
Using default value 312076

Command (m for help): p

Disk /dev/vda: 161.1 GB, 161061273600 bytes
16 heads, 63 sectors/track, 312076 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e1aeb

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *           3         206      102400   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2             206       62416    31353856   8e  Linux LVM
Partition 2 does not end on cylinder boundary.
/dev/vda3           62417      312076   125828640   83  Linux #新加了个分区,所有剩余空间都搞这了

Command (m for help): t #修改分区类型
Partition number (1-4): 3 #选择修改的分区号
Hex code (type L to list codes): 8e #8e为lvm的分区类型
Changed system type of partition 3 to 8e (Linux LVM)

Command (m for help): p

Disk /dev/vda: 161.1 GB, 161061273600 bytes
16 heads, 63 sectors/track, 312076 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e1aeb

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *           3         206      102400   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2             206       62416    31353856   8e  Linux LVM
Partition 2 does not end on cylinder boundary.
/dev/vda3           62417      312076   125828640   8e  Linux LVM #修改成功

Command (m for help): w #w为写入分区并保存。
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

[root@ckcest08 ~]# partprobe #让内核加载新的分区表

[root@ckcest08 ~]# reboot #最好重启,若是新分区标加载成功可以不重启。

[root@ckcest08 ~]# pvscan #目前pv只有一个vda2在
  PV /dev/vda2   VG vg_ckcest07   lvm2 [29.90 GiB / 0    free]
  Total: 1 [29.90 GiB] / in use: 1 [29.90 GiB] / in no VG: 0 [0   ]

[root@ckcest08 ~]# pvcreate /dev/vda3 #将vda3也创建成pv,
 Physical volume "/dev/vda3" successfully created

[root@ckcest08 ~]# pvscan
  PV /dev/vda2   VG vg_ckcest07     lvm2 [29.90 GiB / 0    free]
  PV /dev/vda3                      lvm2 [120.00 GiB] #vda3成功加入
  Total: 2 [149.90 GiB] / in use: 1 [29.90 GiB] / in no VG: 1 [120.00 GiB]

[root@ckcest08 ~]# vgdisplay #vg目前只有30G
  --- Volume group ---
  VG Name               vg_ckcest07
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               4
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               29.90 GiB
  PE Size               4.00 MiB
  Total PE              7654
  Alloc PE / Size       7654 / 29.90 GiB
  Free  PE / Size       0 / 0   
  VG UUID               rjJTHk-dOjL-mWQ8-I4FK-ukqW-OQvr-58Ro6Y

[root@ckcest08 ~]# vgextend vg_ckcest07 /dev/vda3 #将vda3分区的容量加入vg
  Volume group "vg_ckcest07" successfully extended

[root@ckcest08 ~]# vgdisplay #变成150G了。
  --- Volume group ---
  VG Name               vg_ckcest07
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               4
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               149.89 GiB
  PE Size               4.00 MiB
  Total PE              38373
  Alloc PE / Size       7654 / 29.90 GiB
  Free  PE / Size       30719 / 120.00 GiB
  VG UUID               rjJTHk-dOjL-mWQ8-I4FK-ukqW-OQvr-58Ro6Y

[root@ckcest08 ~]# lvdisplay #因为做基类镜像时就都做了lvm所以有这么多,这里只需要将vg的剩余容量挂载到根目录下即可
  --- Logical volume ---
  LV Path                /dev/vg_ckcest07/LogVol01
  LV Name                LogVol01
  VG Name                vg_ckcest07
  LV UUID                QUPJNF-mUkd-9DNx-H02e-UvvN-pz4X-oga4Tt
  LV Write Access        read/write
  LV Creation host, time ckcest07, 2016-08-04 17:11:32 +0800
  LV Status              available
  # open                 1
  LV Size                100.00 MiB
  Current LE             25
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_ckcest07/LogVol00
  LV Name                LogVol00 #这个lv是挂载到/home下
  VG Name                vg_ckcest07
  LV UUID                PGkJ9t-BdF3-GG0r-P2FM-TSbX-J2ND-K3T8iB
  LV Write Access        read/write
  LV Creation host, time ckcest07, 2016-08-04 17:11:32 +0800
  LV Status              available
  # open                 1
  LV Size                10.00 GiB
  Current LE             2560
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/vg_ckcest07/LogVol03
  LV Name                LogVol03
  VG Name                vg_ckcest07
  LV UUID                fOFqir-sIhU-0tBP-9a4C-tbiz-fufG-rQzrgF
  LV Write Access        read/write
  LV Creation host, time ckcest07, 2016-08-04 17:11:35 +0800
  LV Status              available
  # open                 1
  LV Size                19.70 GiB #这个lv挂载到根目录下
  Current LE             5044
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/vg_ckcest07/LogVol02
  LV Name                LogVol02 #这个lv挂载到/tmp下
  VG Name                vg_ckcest07
  LV UUID                TDEt0k-HW0p-mhZZ-UQew-t3hn-ysLs-oRykxd
  LV Write Access        read/write
  LV Creation host, time ckcest07, 2016-08-04 17:11:38 +0800
  LV Status              available
  # open                 1
  LV Size                100.00 MiB
  Current LE             25
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3
   
[root@ckcest08 ~]# lvresize -l +100%FREE /dev/vg_ckcest07/LogVol03 #将vg剩余空间挂载到根目录下
  Extending logical volume LogVol03 to 139.70 GiB
  Logical volume LogVol03 successfully resized

[root@ckcest08 ~]# resize2fs /dev/vg_ckcest07/LogVol03 #重新加载分区大小..等待他加载完成。
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_ckcest07/LogVol03 is mounted on /; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 9
Performing an on-line resize of /dev/vg_ckcest07/LogVol03 to 36621312 (4k) blocks.
The filesystem on /dev/vg_ckcest07/LogVol03 is now 36621312 blocks long.

[root@ckcest08 ~]# df -h
文件系统          容量  已用  可用 已用%% 挂载点
/dev/mapper/vg_ckcest07-LogVol03
                      138G  2.0G  129G   2% / #磁盘空间都挂载来了,done
tmpfs                 939M     0  939M   0% /dev/shm
/dev/vda1              97M   33M   60M  35% /boot
/dev/mapper/vg_ckcest07-LogVol00
                      9.9G  151M  9.2G   2% /home
/dev/mapper/vg_ckcest07-LogVol02
                       97M  5.6M   87M   7% /tmp



三、KVM克隆虚拟机