I am trying to perform offline migration (i.e) Create an incremental image using the qcow format, transfer the vm memory state to a state fie.Use the image and statefile together as a template. Now create a new vm using the template. I can successfully do it using the following commands :
Save phase :
migrate "exec:gzip -c > STATEFILE.gz"
qemu-img create -b BASE_img -f qcow2 INCRE_img
Restore phase :
qemu-kvm -m 1024 -hda INCRE_img -incoming "exec: gzip -c -d STATEFILE.gz"
And it works fine. But I am not able to find the vm with virt-manager or other libvirt based tools.
If I use :
virsh save <dom_id> STATEFILE
I can restore using "virsh restore STATEFILE" but I want to associate this with the incremental image that I created, but I dont know how. I think it saves the existing vm's xml file along with the STATEFILE, thus I am not able to change the disk image to the incremental image.
1. Either I should find a way to make vms created using qemu-kvm appear in libvirt-based tools.
2. Find a way to associate the virsh save STATEFILE with a incremental image.
Any help or hint with respect to these will be very helpful. I am try to do cloning with minimal cost. This takes only 25 seconds ( to create STATEFILE) and creating incremental image is instantatenous . But I want to use the vm monitoring code based on libvirt. And it makes life difficult.
Thanks for your help.
Graduate Student - NC state University
M.S in Computer Science