View disk formats:
[root@ehs-as-04 ehs-rac-01]# cd /var/lib/libvirt/images/ [root@ehs-as-04 images]# qemu-img info ehs-rac-01.qcow2 image: ehs-rac-01.qcow2 file format: qcow2 virtual size: 30G (32212254720 bytes) disk size: 34G cluster_size: 65536 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 ehs-rac-01-bak 1.6G 2019-09-09 16:00:13 00:16:16.672 2 ehs-rac-01-bak02 1.9G 2019-09-09 16:04:40 00:20:27.294 Format specific information: compat: 1.1 lazy refcounts: true
Because kvm virtual machines using the default raw format image format, the performance of the best, fastest, its drawback is that does not support some new features, such as support for mirroring, zlib disk compression, AES encryption. To use mirroring, disk format must be qcow2. If the format is raw, you need to convert. We can see a mirror image of the grid is qcow2, so no need to change the image format.
Disk format conversion
[EHS-AS- the root @ 04 Images] -f # QEMU Convert RAW -O-IMG qcow2 of rac- EHS- 01 .img of rac- EHS- 01 .qcow2 - Format of the mirror f -O target image format
Virtual machine snapshot management
Create a snapshot
[root @ EHS-AS- 04 ImagesRF Royalty Free] # virsh the Create Snapshot-EHS-rac-Ethyl 01 ## can also give a snapshot from the alias [root @ EHS -as- 04 ImagesRF Royalty Free] # virsh the Create Snapshot-AS-EHS-rac-Ethyl 01 EHS-rac-Ethyl 01 -bak
View snapshot version
[EHS-AS- the root @ 04 Images] # virsh Snapshot-List of rac- EHS- 01 Name Generation Time Status -------------------------- ---------------------------------- EHS -rac- 01 -bak 2019 - 09 - 09 16 : 00 : 13 is + 0800 running EHS -rac- 01 -bak02 2019 - 09 - 09 16 : 04 : 39 + 0800 running
View the current version of the virtual machine snapshot
[root@ehs-as-04 images]# virsh snapshot-current ehs-rac-01 <domainsnapshot> <name>ehs-rac-01-bak02</name> <state>running</state> <parent> <name>ehs-rac-01-bak</name> </parent> <creationTime>1568016279</creationTime> <memory snapshot='internal'/> <disks> <disk name='hda' snapshot='internal'/> <disk name='hdb' snapshot='no'/> </disks> ...
View the current image file:
[root@ehs-as-04 images]# qemu-img info ehs-rac-01.qcow2 image: ehs-rac-01.qcow2 file format: qcow2 virtual size: 30G (32212254720 bytes) disk size: 34G cluster_size: 65536 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 ehs-rac-01-bak 1.6G 2019-09-09 16:00:13 00:16:16.672 2 ehs-rac-01-bak02 1.9G 2019-09-09 16:04:40 00:20:27.294 Format specific information: compat: 1.1 lazy refcounts: true
Snapshot configuration file in the / var / lib / libvirt / qemu / snapshot / virtual machine name
[EHS-AS- the root @ 04 Images] # LL / var / lib / the libvirt / QEMU / Snapshot / EHS of rac-- 01 / Total amount 16 -rw ------- . 1 the root the root 5250 . 9 dated . 9 16 : 04 EHS-rac-Ethyl 01 - bak02.xml -rw ------- 1 root root 5193 9 Yue 9 16 : 04 EHS-rac-Ethyl 01 -bak.xml
Restore virtual machine snapshots
Note: Recovery Snapshot, must be shut down, make sure the virtual machine is turned off.
[root@ehs-as-04 images]# virsh destroy ehs-rac-01 域 ehs-rac-01 被删除 [root@ehs-as-04 images]# virsh list --all Id 名称 状态 ---------------------------------------------------- 10 ehs-jboss-02 running 14 ehs-mq-02 running 15 ehs-jboss-01 running 17 ehs-mq-01 running 23 ehs-rac-02 running - ehs-oracle-01 关闭 - ehs-oracle-02Close - EHS rac-Ethyl- 01 closed
Snapshot version or time recognized the need to restore, where to restore ehs-rac-01-bak02
[EHS-AS- the root @ 04 Images] # virsh Snapshot-List of rac- EHS- 01 Name Generation Time Status -------------------------- ---------------------------------- EHS -rac- 01 -bak 2019 - 09 - 09 16 : 00 : 13 is + 0800 running EHS -rac- 01 -bak02 2019 - 09 - 09 16 : 04 : 39 + 0800 running
Performing a recovery
[root@ehs-as-04 images]# virsh snapshot-revert ehs-rac-01 ehs-rac-01-bak02
If the recovery time needed to ehs-rac-01-bak02 modification timestamp
[root@ehs-as-04 images]# virsh snapshot-revert ehs-rac-01 1500373324
To delete a virtual machine snapshot
First ehs-rac-01 image corresponding to a snapshot of what
[root@ehs-as-04 images]# qemu-img info ehs-rac-01.qcow2 image: ehs-rac-01.qcow2 file format: qcow2 virtual size: 30G (32212254720 bytes) disk size: 34G cluster_size: 65536 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 ehs-rac-01-bak 1.6G 2019-09-09 16:00:13 00:16:16.672 2 ehs-rac-01-bak02 1.9G 2019-09-09 16:04:40 00:20:27.294 Format specific information: compat: 1.1 lazy refcounts: true
Remove the first snapshot
[root @ EHS-AS- 04 ImagesRF Royalty Free] # virsh the Delete Snapshot EHS-rac-Ethyl- 01 EHS-rac-Ethyl 01 - BAK deleted domain snapshots EHS -rac- 01 -bak
Look for confirmation
[EHS-AS- the root @ 04 Images] # virsh Snapshot-List of rac- EHS- 01 Name Generation Time Status -------------------------- ---------------------------------- EHS -rac- 01 -bak02 2019 - 09 - 09 16 : 04 : 39 + 0800 running
It has been deleted.