tech:server:linux:virtualization:kvm-qemu:qemu-img:qemu-img
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Table of Contents
qemu-img
DO NOT OPERATE ANY MODIFICATION COMMAND(INCLUDING SNAPSHOT OPERATION) ON RUNNING VIRTUAL MACHINE IMAGE!!!!!!!
THE OPERATIONS RESULTS IN VIRTUAL MACHINE IMAGE CORRUPTION, LOSE ALL DATA!!!!!!!!!!
MAKE SURE TARGET VM STOPPED THAT CONTAINS THE VM IMAGE.
root@hotaru:/var/lib/libvirt/images# virsh list --inactive | fgrep nextcloud1.example.com - nextcloud1.example.com shut off
- list snapshots.
qemu-img snapshot -l nextcloud1.example.com.qcow2
if no snapshots found, result is empty.
- create a snapshot.
qemu-img snapshot -c "Initial snapshot" nextcloud1.example.com.qcow2
list again.
root@hotaru:/var/lib/libvirt/images# qemu-img snapshot -l nextcloud1.example.com.qcow2 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 Initial snapshot 0 2020-01-06 21:53:18 00:00:00.000
snapshot was created successfully.
4 or more snapshots exists, in my experience, VM performance significantly decrease….
- revert to snapshot
root@hotaru:~# qemu-img snapshot -l /var/lib/libvirt/images/nextcloud1.example.com.qcow2 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 Initial snapshot 0 2020-01-06 21:53:18 00:00:00.000 root@hotaru:~# qemu-img snapshot -a 1 /var/lib/libvirt/images/nextcloud1.example.com.qcow2
- remove snapshot
root@hotaru:~# qemu-img snapshot -l /var/lib/libvirt/images/nextcloud1.example.com.qcow2 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 Initial snapshot 0 2020-01-06 21:53:18 00:00:00.000 root@hotaru:~# qemu-img snapshot -c "virt-sysprep" /var/lib/libvirt/images/nextcloud1.example.com.qcow2 root@hotaru:~# qemu-img snapshot -l /var/lib/libvirt/images/nextcloud1.example.com.qcow2 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 Initial snapshot 0 2020-01-06 21:53:18 00:00:00.000 2 virt-sysprep 0 2020-01-07 07:05:09 00:00:00.000 root@hotaru:~# qemu-img snapshot -d 1 /var/lib/libvirt/images/nextcloud1.example.com.qcow2 root@hotaru:~# qemu-img snapshot -l /var/lib/libvirt/images/nextcloud1.example.com.qcow2 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 2 virt-sysprep 0 2020-01-07 07:05:09 00:00:00.000
Resize QCOW2 image size
qemu-img resize nextcloud1.example.com.qcow2 20G
root@hotaru:/var/lib/libvirt/images# qemu-img resize nextcloud1.example.com.qcow2 20G qemu-img: Can't resize an image which has snapshots
References
tech/server/linux/virtualization/kvm-qemu/qemu-img/qemu-img.1578808365.txt.gz · Last modified: 2020/01/12 14:52 by wnoguchi
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