[draft] Как сделать бекап вирутальной машины KVM

• http://serverfault.com/questions/707544/exporting-libvirtkvm-virtual-machines-to-files
• https://help.ubuntu.com/community/KVM/Virsh
• https://www.reddit.com/r/linuxadmin/comments/3el6ao/correct_way_to_export_a_kvm_virtual_machine/
• https://pve.proxmox.com/wiki/Shrink_Qcow2_Disk_Files
• https://www.jamescoyle.net/how-to/323-reclaim-disk-space-from-a-sparse-image-file-qcow2-vmdk
• http://serverfault.com/questions/329287/free-up-not-used-space-on-a-qcow2-image-file-on-kvm-qemu
• https://rwmj.wordpress.com/2010/05/18/tip-compress-raw-disk-images-using-qcow2/