KVM Snapshotting and Cloning 101
Snapshotting
First the VM must be in qcow2 format. Do this to check:
virsh dumpxml nsx.example.com | grep -i qemu <emulator>/usr/libexec/qemu-kvm</emulator> <driver name='qemu' type='qcow2'/>
Next do this:
virsh snapshot-create-as --domain nsx.example.com --name "04nov2023s0" --description "test" --live error: Operation not supported: live snapshot creation is supported only with external checkpoints
The confusing message will go away once you drop --live.
To see the snapshot(s):
virsh snapshot-list --domain nsx.example.com Name Creation Time State ------------------------------------------------------------ 04nov2023s0 2023-11-04 12:07:48 +0200 running
Cloning
Suspend the machine:
virsh suspend ns2.vander.host Domain ns2.vander.host suspended
Try prompt and fail:
virt-clone --prompt WARNING --prompt mode is no longer supported. ERROR Either --auto-clone or --file is required, use '--auto-clone or --file' and try again.
Do manual cloning using the command line:
virt-clone -o nsx.example.com -n nsx.example.com.clone -f ./nsx.example.com.clone.raw WARNING Setting the graphics device port to autoport, in order to avoid conflicting. Allocating 'nsx.example.com.clone.raw' | 10 GB 00:06:22 Clone 'nsx.example.com.clone' created successfully.
It took around 6 minutes to clone 10 gigabytes.
Then copy it to another hypervisor took quite long:
> 9668MB 49.0MB/s 03:17