[Qemu-devel] Taking live snapshots of running VMs

[Ahmed M. Azab]

Hi All,

Is there a way to take a live memory snapshot of a running VM without
freezing or stopping this VM?

I explored the Qemu code and documentation and I found two ways to
take a snapshot:

1-Using "savevm" Qemu monitor command, which freezes the VM for tens of seconds
2-Using "migrate" and select the destination as a file, which forces
the machine to stop after the snapshot is saved.

In production environments (where delaying the operations of a VM is
very critical), it is always useful to take memory snapshots to do
system analysis or forensics. I think Qemu should provide a way to
take a snapshot based on QOW technque of memory pages (same as the
QCOW disk snapshoting).

If such technique does not exist, I am willing it devlop it myself,
but I wonder if the Qemu community will be interested to add my patch
to future versions.

Ahmed