Wide-area migration of Virtual Machines including local persistent state
So far virtual machine (VM) migration has focused on transferring the
run-time memory state of the VMs in local-area networks (LAN).
However, for wide-area network (WAN) migration it is crucial to not
just transfer the VMs image but also transfer its local persistent
state (e.g. file system), and its on-going network connections. In
this paper we address both: by combining a block-level solution with
pre-copying and write throttling we show that we can transfer an
entire running web server (including its local persistent state) with
minimal disruption (three seconds in the LAN and 68 seconds in the
WAN); by combining dynDNS with tunneling, existing connections can
continue transparently while new ones are redirected to the new
network location. Thus we show experimentally that by combining
well-known techniques in a novel manner we can provide system support
for migrating virtual execution environments in the wide area.