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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）查看现有磁盘的格式
| 1 2 3 4 5 | [root@KVM test ] # qemu-img info hadoop3.img image: hadoop3.img file format : raw virtual size: 10G (10737418240 bytes) disk size: 877M |
把raw格式转换成qcow2格式
（2）关闭需要转换磁盘的虚拟机
| 1 2 3 4 5 6 7 8 9 10 | [root@KVM test ] # virsh destroy hadoop3 Domain hadoop3 destroyed [root@KVM test ] # virsh list --all Id Name State ---------------------------------------------------- 1 win7 running 6 hadoop2 running - hadoop1 shut off - hadoop3 shut off - hadoop4 shut off |
（3）转换磁盘的格式
| 1 | [root@KVM test ] # qemu-img convert -f raw -O qcow2 hadoop3.img hadoop3.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
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | [root@KVM test ] # qemu-img convert -f raw -O qcow2 hadoop3.img hadoop3.qcow2 [root@KVM test ] # ll total 14975352 -rwxr-xr-x 1 root root 10737418240 Feb 4 14:38 hadoop1.img -rwxr-xr-x 1 qemu qemu 10737418240 Feb 4 16:51 hadoop2.img -rwxr-xr-x 1 root root 10737418240 Feb 4 16:48 hadoop3.img -rw-r--r-- 1 root root 923926528 Feb 4 16:51 hadoop3.qcow2 -rwxr-xr-x 1 root root 10737418240 Feb 4 15:11 hadoop4.img -rwxr-xr-x 1 qemu qemu 8589934592 Feb 2 15:03 win7.img [root@KVM test ] # qemu-img info hadoop3.qcow2 image: hadoop3.qcow2 file format : qcow2 virtual size: 10G (10737418240 bytes) disk size: 881M cluster_size: 65536 |
2，修改虚拟机配置文件
| 1 | [root@KVM qemu] # virsh edit hadoop3 |
<domain type='qemu'>
<name>hadoop3</name>
<uuid>586b3cae-943f-e283-d8e7-ed72b01bfa34</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='/images/test/hadoop3.qcow2'/>
<target dev='hda' bus='ide'/>
3，对虚拟机进行快照管理
(1)对hadoop3虚拟机创建快照
| 1 2 | [root@KVM qemu] # virsh snapshot-create hadoop3 Domain snapshot 1454577228 created |
（2）查看虚拟机快照的版本
| 1 2 3 4 | [root@KVM qemu] # virsh snapshot-list hadoop3 Name Creation Time State ------------------------------------------------------------ 1454577228 2016-02-04 17:13:48 +0800 shutoff |
（3）查看当前虚拟机镜像快照的版本
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 | [root@KVM qemu] # virsh snapshot-current hadoop3 <domainsnapshot> <name>1454577442< /name > <state>shutoff< /state > <parent> <name>1454577228< /name > < /parent > <creationTime>1454577442< /creationTime > <memory snapshot= 'no' /> <disks> <disk name= 'hda' snapshot= 'internal' /> <disk name= 'hdc' snapshot= 'no' /> < /disks > <domain type = 'qemu' > <name>hadoop3< /name > <uuid>586b3cae-943f-e283-d8e7-ed72b01bfa34< /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 = '/images/test/hadoop3.qcow2' /> <target dev= 'hda' bus= 'ide' /> <address type = 'drive' controller= '0' bus= '0' target= '0' unit= '0' /> < /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 = 'network' > <mac address= '52:54:00:fe:f5:a3' /> < source network= 'default' /> <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= '5913' 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= '0x05' function = '0x0' /> < /memballoon > < /devices > < /domain > < /domainsnapshot > |
（4)查看当前虚拟机镜像文件，快照文件的路径在/var/lib/libvirt/qemu/snapshot/ 下
| 1 2 3 4 | [root@KVM qemu] # ll /var/lib/libvirt/qemu/snapshot/hadoop3/ total 8 -rw------- 1 root root 3402 Feb 4 17:17 1454577228.xml -rw------- 1 root root 3453 Feb 4 17:17 1454577442.xml |
4，恢复虚拟机快照
（1）恢复虚拟机快照必须关闭虚拟机
| 1 2 3 4 5 6 7 8 | [root@KVM qemu] # virsh list --all Id Name State ---------------------------------------------------- 1 win7 running 6 hadoop2 running - hadoop1 shut off - hadoop3 shut off - hadoop4 shut off |
（2）确认恢复快照的时间，这里是恢复到1454577442
| 1 2 3 4 5 | [root@KVM qemu] # virsh snapshot-list hadoop3 Name Creation Time State ------------------------------------------------------------ 1454577228 2016-02-04 17:13:48 +0800 shutoff 1454577442 2016-02-04 17:17:22 +0800 shutoff |
（3）执行恢复，并确认恢复版本
| 1 2 | [root@KVM qemu] # virsh snapshot-revert hadoop3 1454577442 [root@KVM qemu] # virsh snapshot-current hadoop3 |
5，删除虚拟机快照
（1）查看虚拟机快照
| 1 2 3 4 5 6 7 8 9 10 | [root@KVM test ] # qemu-img info hadoop3.qcow2 image: hadoop3.qcow2 file format : qcow2 virtual size: 10G (10737418240 bytes) disk size: 881M cluster_size: 65536 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 1454577228 0 2016-02-04 17:13:48 00:00:00.000 2 1454577442 0 2016-02-04 17:17:22 00:00:00.000 |
(2)删除快照
| 1 2 3 4 5 6 7 8 9 10 11 | [root@KVM test ] # virsh snapshot-delete hadoop3 1454577228 Domain snapshot 1454577228 deleted [root@KVM test ] # qemu-img info hadoop3.qcow2 image: hadoop3.qcow2 file format : qcow2 virtual size: 10G (10737418240 bytes) disk size: 881M cluster_size: 65536 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 2 1454577442 0 2016-02-04 17:17:22 00:00:00.000 |
至此虚拟机快照从创建，查看，删除。如果有报错，再一一的进行拍错。
本文转自 lqbyz 51CTO博客，原文链接:http://blog.51cto.com/liqingbiao/1741125
转载地址：http://onxkm.baihongyu.com/