kvm虚拟化学习笔记(十)之kvm虚拟机快照备份

2021-08-11 20:16:05

kvm虚拟机默认使用raw格式的镜像格式，性能最好，速度最快，它的缺点就是不支持一些新的功能，如支持镜像,zlib磁盘压缩,AES加密等。
要使用镜像功能，磁盘格式必须为qcow2。下面开始kvm虚拟机快照备份的过程。

1. 查看现有磁盘镜像格式与转换

(1) 查看磁盘格式

# qemu-img info CentOS6.5-01.img

raw格式需要转换成qcow2

(2) 关闭虚拟机并转换磁盘

# virsh shutdown CentOS6.5-01

(3) 转换磁盘格式

# qemu-img convert -f raw -O qcow2 CentOS6.5-01.img CentOS6.5-01.qcow2

-f 源镜像的格式
-O 目标镜像的格式

查看转换后的格式，已经转换成了qcow2, 这里是拷贝一份，并将格式转成qcow2

# qemu-img info CentOS6.5-01.qcow2

2. 修改虚拟机配置文件

修改磁盘格式，与新qcow2格式的磁盘。

3. 对虚拟机进行快照管理

(1) 对CentOS6.5-01虚拟机创建快照

# virsh snapshot-create CentOS6.5-01

也可以virsh snapshot-create as CentOS6.5-01 snap1 创建后个快照别名。

(2) 查看虚拟机镜像快照的版本

# virsh snapshot-list CentOS6.5-01

(3) 查看当前虚拟机镜像快照的版本

可以看到为当前最新的快照版本。

[root@node1 kvm]# virsh snapshot-current CentOS6.5-01
<domainsnapshot>

  <name>1511337772</name>

  <state>shutoff</state>

  <creationTime>1511337772</creationTime>

  <memory snapshot='no'/>

  <disks>

    <disk name='vda' snapshot='internal'/>

    <disk name='hdc' snapshot='no'/>

  </disks>

  <domain type='kvm'>

    <name>CentOS6.5-01</name>

    <uuid>7d48f7b5-2fbf-91a9-2c3f-e52ba6079c8e</uuid>

    <memory unit='KiB'>1048576</memory>

    <currentMemory unit='KiB'>1048576</currentMemory>

    <vcpu placement='static'>1</vcpu>

    <os>

      <type arch='x86_64' machine='rhel6.6.0'>hvm</type>

      <boot dev='hd'/>

    </os>

    <features>

      <acpi/>

      <apic/>

      <pae/>

    </features>

    <clock offset='localtime'/>

    <on_poweroff>destroy</on_poweroff>

    <on_reboot>restart</on_reboot>

    <on_crash>restart</on_crash>

    <devices>

      <emulator>/usr/libexec/qemu-kvm</emulator>

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

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

        <source file='/data/kvm/CentOS6.5-01.qcow2'/>

        <target dev='vda' bus='virtio'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>

      </disk>

      <disk type='block' device='cdrom'>

        <driver name='qemu' type='raw'/>

        <target dev='hdc' bus='ide'/>

        <readonly/>

        <address type='drive' controller='0' bus='1' target='0' unit='0'/>

      </disk>

      <controller type='usb' index='0' model='ich9-ehci1'>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x7'/>

      </controller>

      <controller type='usb' index='0' model='ich9-uhci1'>

        <master startport='0'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='on'/>

      </controller>

      <controller type='usb' index='0' model='ich9-uhci2'>

        <master startport='2'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x1'/>

      </controller>

      <controller type='usb' index='0' model='ich9-uhci3'>

        <master startport='4'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x2'/>

      </controller>

      <controller type='ide' index='0'>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>

      </controller>

      <interface type='bridge'>

        <mac address='52:54:00:56:9a:7f'/>

        <source bridge='br0'/>

        <model type='virtio'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

      </interface>

      <serial type='pty'>

        <target port='0'/>

      </serial>

      <console type='pty'>

        <target type='serial' port='0'/>

      </console>

      <input type='mouse' bus='ps2'/>

      <graphics type='vnc' port='5910' autoport='no' listen='0.0.0.0'>

        <listen type='address' address='0.0.0.0'/>

      </graphics>

      <video>

        <model type='cirrus' vram='9216' heads='1'/>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>

      </video>

      <memballoon model='virtio'>

        <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>

      </memballoon>

    </devices>

  </domain>

</domainsnapshot>
 
[root@node1 kvm]#