My next step:
I created new booting virtual disk in VM machine.
I converted disk with snapshot to raw disk
#>qemu-img convert -f qcow2 -O raw name_of_snapshot_qcow2 name_of_new_disk_image
Then replaced the created virtual machine disk image with this file
(name_of_new_disk_image).
Strahil, thank you very mach for help!!!