kvm初体验之九：vm创建快照

1. 准备一个磁盘格式为qcow2的vm（raw格式的磁盘无法创建快照）

方法一：从头安装一个磁盘格式为qcow2的vm

[root@tanghuimin vm]# qemu-img create -f qcow2 -o preallocation=metadata /vm/vm2.qcow2 2G

Formatting '/vm/vm2.qcow2', fmt=qcow2 size=2147483648 encryption=off cluster_size=65536 preallocation='metadata'

[root@tanghuimin vm]# qemu-img info vm2.qcow2

image: vm2.qcow2

file format: qcow2

virtual size: 2.0G (2147483648 bytes)

disk size: 464K

cluster_size: 65536

virt-install --name vm2 --vcpus=1 --ram=1024 --disk
path=/vm/vm2.qcow2,format=qcow2
--cdrom /root/iso/CentOS-6.6-x86_64-minimal.iso --network
bridge:br0

方法二：将现存的磁盘格式为raw的vm转换成qcow2的磁盘格式

[root@tanghuimin vm]# qemu-img info vm1-clone

image: vm1-clone

file format: raw

virtual size: 2.0G (2147483648 bytes)

disk size: 2.0G

[root@tanghuimin vm]# qemu-img convert -f
raw vm1-clone -O qcow2 vm1-clone.qcow2

[root@tanghuimin vm]# qemu-img info vm1-clone.qcow2

image: vm1-clone.qcow2

file format: qcow2

virtual size: 2.0G (2147483648 bytes)

disk size: 813M

cluster_size: 65536

virsh edit vm1-clone

将

<disk type='file' device='disk'>

<driver name='qemu' type='raw'
cache='none'/>

<source file='/vm/vm1-clone'/>

<target dev='hda' bus='ide'/>

<address type='drive' controller='0' bus='0'
target='0' unit='0'/>

</disk>

修改为

<disk type='file' device='disk'>

<driver name='qemu' type='qcow2'
cache='none'/>

<source file='/vm/vm1-clone.qcow2'/>

<target dev='hda' bus='ide'/>

<address type='drive' controller='0' bus='0'
target='0' unit='0'/>

</disk>

2. 创建快照（virsh
snapshot-create）

virsh # snapshot-list vm2

Name Creation Time State

------------------------------------------------------------

virsh # snapshot-create vm2

Domain snapshot 1433458417 created

virsh #

virsh # snapshot-list vm2

Name Creation Time State

------------------------------------------------------------

1433458417 2015-06-05 06:53:37 +0800 shutoff

3. 从快照恢复（virsh
snapshot-revert）

virsh # snapshot-list vm2

Name Creation Time State

------------------------------------------------------------

1433458417 2015-06-05 06:53:37 +0800 shutoff

virsh # snapshot-revert vm2 1433458417

4. 删除快照（virsh
snapshot-delete）

virsh # snapshot-list vm2

Name Creation Time State

------------------------------------------------------------

1433458417 2015-06-05 06:53:37 +0800 shutoff

virsh #

virsh # snapshot-delete vm2 1433458417

Domain snapshot 1433458417 deleted

virsh # snapshot-list vm2

Name Creation Time State

------------------------------------------------------------